Touchpad & trackpoint buttons strange behaviour

[Kardell2]

My friends Thinkpad X31 has certain problem with trackpoint and touchpad buttons.
Right one don't work at all and left one behave like left and right in the same time.
When I click left trackpoint or touchpad button it always open popup action (Desktop properties etc.) assigned to the right one.
And this left button behave more often as right one blocking specific left button operations. To unlock it I have to start Task Manager.
This solution is only temporary.
I sense hardware related issue, because I've reinstalled os, and still experience the same thing.
As I investigated there was some minor tea spillage (some time before this issue appeared), however when I opened the case and remove the keyboard it looks ok, the buttons works normally.
Thank you for any clues or ideas.