Key problem - CCM?

We have a 2001 Fabia 1.9 Tdi hatchback owned from new, annually serviced and always garaged.  103k and great condition. Last week,  when I went to open the car with the key remote first time that the day, the door would open, but it also started sounding the alarm siren.  The rest of the day it would behave normally.  I took it into my local general service garage and they checked it for computer faults:

2 Faults Found:
01134 - Alarm Horn (H12)
            49-10 - No Communications - Intermittent
01135 - Interior Monitoring Sensors
            36-10 - Open Circuit - Intermittent

They did various minor things, sprayed contacts, changed batteries in keys, etc. and said it appeared to be working normally.  Since then, when I try to open the car with the remote button, first the red light goes out (on the driver's door by the button) but nothing else happens. Then after repeated remote clicking eventually the driver's door unlocks and the indicators light up and stay on for many seconds.  Then more remote clicks and eventually the other doors unlock.  Then, with a few extra clicks of the remote, it becomes more responsive and locks/unlocks fairly normally.  Next day the darned thing won't unlock again and it's back to manic clicking...

A friend says it may be that the CCM is packing up.  He says that my part number is 6Q0959433C, and that there's a couple of slightly later versions (with an "E" suffix) on eBay at the moment for ~30 quid.

Please can anyone tell me if we're on the right track (or not) and if so, if the E suffix CCM's will do for my car.  Many thanks in advance.