Have just installed a 500Gb Western Digital Caviar Blue PATA HDD to a relatives Thomson DSI6210 box.Removing the old drive and fitting the new one is a bit more of a fiddle than other boxes I've done due to the large plastic cradle the HDD sits in , but once fitted I performed a full system reset from the installer menu - 5 minutes later the box was up and running , this method obviously losing all previously recorded programs , but , if you can live with this , it's a cheap and cheerful method for those who don't already possess the computer power supply and PATA connectors necessary to do a disc to disc copy.
Although it's early days I haven't had reports of any problems with the box and even the fan operates normally.Here are some details to help nail down compatibility for anyone thinking of doing an upgrade to this ageing pvr.
Thomson Model Number - 1301167
Version Number - 4E2002
Operating System Version - 1.31B10
EPG Software Version - 5.07.U
Hard Disk Removed - Maxtor 160Gb
Hard Disk Fitted - Western Digital Caviar SE16 500Gb U133 with 16Mb cache (WD5000AAKB)