I'm having a problem with the 'widescreen flag'. Some widescreen programmes that I've recorded onto HDD and then transferred to DVD preserve the widescreen flag, but others
don't.

For example, Titanic: Birth of a Legend, recorded from ITV1 recently, switches my TV (Sony Wega 28") into 16:9 perfectly but Harry Potter and the Philosopher's Stone recorded from BBC1 over Christmas, doesn't.

Any suggestions?

I've found it is possible to record the flag but the Pioneer can be finicky sometimes.
If the original HDD recording of Harry Potter works correctly then a transfer to -R will preserve the flag,however ,along with self selected chapter stops,this is only retained with a high speed copy.
If you reencode inreal time using the OPTIMISE setting,the WSS flag is lost.
A PC burner and IFO edit can add it back.
Just burn to -RW,copy that to PC HDD,add WSS manually and burn back to-R.
When recording from Sky or Freeview to the Pioneer,always ensure WSS is working before recording commences.If it does not,click the channel up or down one then back again and it should be ok.
But remember that it won't switch between ratios within a single recording.
Was HP copied in real time and Titanic at high speed?

Ah - that's it! It was recorded in SP mode onto HDD but wouldn't fit in its entirety onto one DVD so I allowed it to change the recording mode while archiving, so it did it in real time not in high speed.

Damn!

At least I know what's causing it anyhow.