T400 Motherboard reliability issue

[Mikinoz]

We have recently had a few motherboards go on our T400 machines 2765-8VM in particular, the 3g card is not detected any longer and when a new 3g card is inserted or reseated, it as well is not detected. Leading to a motherboard replacement

I was wondering are others finding the same ?
Could this be a manufacturing fault (still burnt from several T4X's & T3X)?
Do any others work or support a number of these machines and use the 3g card ?

We have 30 units approx, and in the last 2 months we have had 3 that have been/needed repair just for this reason.

Thank you

Mike