Does the PVR button on the handset light up when you press them?
Is it actually that all the on-screen activity appears normal but you are just not being allowed to delete the recording?
If it is the latter, there is a simple answer: you can't delete a recording that is currently paused. If you do not allow the recording to play until the end (eg you change back to live TV or play something else because the programme in the recording has finished but the recording itself has not reached the end), you must stop the playback with the stop button to release it. Play the recording again, and stop it with the stop (square) button. Then the delete options will be unlocked.
Thanks for advice which is useful, however, the problem is that there is no reaction to the Media or Opt+ buttons so I cannot complete playing the recorded item! which I had fast forwarded to the end, and then the no button action
OK, that's weird then. I don't think we have heard of this exact problem before, and will only be able to suggest ideas.
Ensure there are absolutely no possible sources of interfering IR radiation;
Reboot the handset and reset the control channel number;
Warranty return - it has been known for the IR receiver module to malfunction;
Reload the firmware;
Use custom firmware to check the file system for errors (and fix them);
Use standard menus to reformat the HDD (destructive of your recordings);
Beyond those you have already tried, I can't think of any other options (in a non-custom firmware environment).
If you are a custom firmware user, make sure you have not set up the ir package to cream off the button presses, even accidentally, and use the virtual remote control to inject the button presses to see if they work that way. It is also possible to monitor the incoming commands.