I've Emailed Humax Support with this issue but though I'd share my experiences on the forum in case this is affecting other people as well:

I've noticed an issue over the 2 years I've had the Humax (bought Oct/Nov 2005) that if I see it finish recording a programme and go into standby and I bring it back out of standby too quickly (e.g after leaving it about 30 seconds) and try to view a recorded programme the box locks up immediately. The only way out is to power off and on using the switch at the rear. Having done that I can then view the programme okay.

I have had the issue on different levels of software. I'm currently on 1.00.21.

So my question is: How long should I leave it before bring it out of standby once it has gone into standby?

More information: I have the box record Channel 4 News at Noon every day, scheduled from 12:00 to 12:30 approx. The Humax is usually on BBC News 24 as the channel to display on the TV. Normally when I arrive to watch it it is around 12:27-12:29 so I quickly press the power button on the remote to keep the box from going into standby and there is no problem. Or I don't arrive till 12:35 or later in which case the box has gone into standby because the programme has finished at least 5 minutes beforehand and again there is no problem. But if there is not much of a gap between the programme ending, the box going into standby, and me bringing it out of standby just 30 seconds later, it will lock up. This is what happened today as an example:

5/2/2008. 12:33. The Humax went into standby having finished recording Channel 4 News at Noon. I left it about 30 seconds and brought the machine out of standby. The box came on with BBC News 24 being displayed on the front panel and the TV screen as expected. I went into the recorded programme list by pulling down the remote handset flap and pressing the top button on the right. Channel 4 News at Noon was already selected as expected so I pressed OK to start viewing the programme as I always do. The BBC News 24 picture disappeared and I was left with just the recorded programme screen with Channel 4 News at Noon selected. I left the box a few minutes hoping it might respond but nothing happened. Pressing the buttons on the remote had no effect.

I had to power the box down and up again using the switch on the back.

The box powered back up and BBC News 24 was being displayed as before. I did exactly the same procedure as before and this time was able to view the recorded Channel 4 News at Noon without any further problems.

When I've upgraded the software each time I've always done a reset to defaults. I formatted the drive a few weeks ago while on 1.00.20, not because of any problems, just because I'd watched and deleted all the recorded programmes and took the opportunity to do the format to ensure all the disk tables were clean having read about other people's problems with corrupt file systems. I used the Crystal Palace MUXes. Signal strength is 69%, signal quality is 100%.

I currently use Accurate Recording and Series link to automatically schedule programmes (including Channel 4 News at Noon), but on previous software versions when this wasn't available I've used AutoPadding except on the early software versions when it wasn't available.

The box is always put into standby when I've finished using it.

To put the problem in perspective though, apart from this one issue which has caught me out about 5 times over the 2+ years I've had it, I'm very very pleased with the 9200T's reliability. The box has been in constant use since Oct/Nov 2005, automatically recording (via timers) and viewing several hours of TV programmes on a daily basis. In all that time, and with all the use it has had, I can't say I've had any real problems with it unlike other makes of PVRs I've had.

60s.

Thanks. I did actually get a reply yesterday afternoon from Humax asking me to do the usual reset to defaults but this time with the aerial unplugged.
So I gave it a go today and repeated my actions of 5/2/2008 (bring box back out of standby approx. 30 secs after it going into standby having recorded Channel 4 News at Noon, then try to watch Channel 4 News at Noon).

This time Channel 4 News at Noon did start to display. Immediately, I pressed the stop button for a couple of minutes to bring in my lunch, reselected Channel 4 News at Noon and it froze immediately (both picture and sound).

I had to power it off/on round the back to get out of it. All okay after that.

I've Emailed Humax with the above.

Digressing slightly but I’ve read unplug the aerial while doing a default settings a few times, does anyone know the thinking behind this?

Immediately after it's done its default it goes into an auto scan. If the aerial is out then it won't find any channels and the list will be clean. If it were necessary to do a mux by mux manual scan then this would be a way of starting with a clean sheet. I don't see the point of doing it this way but it might be their reasoning.

I did get a further reply from Humax, not advising how long it should be left after the box has switched to standby before bringing it back out of standby, but offering me the chance to send the box back and have it repaired or replaced (presumably with a refurbished one).

I decided to decline their offer as although my unit is over 2 years old it has been reliable 99% of the time, didn't want to be without it for a couple of weeks, and didn't want to get a refurbished one that could have significantly more problems than the one I've got.

Thanks to wgmorg for suggesting leaving it 60 seconds before bringing it back out of standby. This has worked fine.

Looking at the LED panel closely, I now realise that when the machine auto switches to standby having finished recording, the REC indicator goes out then it is a number of seconds before the clock symbol appears. A few more seconds on, the clock symbol goes out again, the time briefly goes brighter then back to its original level of illumination, and a few seconds after that the clock symbol reappears again. All this takes around 30 seconds in all.

And sure enough, through further experimentation I've found I can in fact switch it out of standby just over 30 seconds after it auto switches into standby.

I guess the Humax was getting upset and being interrupted during this period of "post recording switch to standby" processing.

No I don't see the reasoning either because you can immediately 'stop' the scan, or simply 'don't save' at the end with the same result. Unplugging the aerial then plugging it back in makes a mockery of the warning label on top of the case.