Occasionally I keep getting phone calls from people saying that they recieved a missed call from me, these are not witheld numbers but they call me from mobiles saying that.

But it is funny they say that because i've noticed a 2 second call to a premium rate number listed on last months bill but charged around 50p for it.

And I check my cordless handset to see what numbers have been dialled but nothing suspicious shows up.

What could this be! Faulty equipment or someone hacking in somewhere???

This is a scam. You get a missed call off a number that appears to be from a mobile, but it is in fact a 'personal' number (starts 070) and as you've noticed it costs upwards of 50p per min to call them.
I believe ofcom are in the process of moving personal numbers to a new prefix and then making all numbers beginning '07' mobile ones. This will cure the problem.

Sounds familiar, look at this post:

http://www.digitalspy.co.uk/forums/s...583&highlight=

I occasionally get calls from an 07033 number The first time it happened,because it wasn`t withheld, I called back..it cost me £2.00 to answer it!!

I didn`t realise that till I called it back again and it used up all my credit