keyboard issues with laptop

[#1]

I posted in the windows section reagrds an HP dv6000 series.  This system is also having keyboard issues, the u ket will mute the sound, v key adjust the volume, j key disable the touchpad, and shift+m refuses to give a capital m, but shiftlock+m will. The keyboard does not do this is FN is pressed with the key, but normal FN functions are OK.f I thought this would go after reformatting, thinking its a windows issue, but it didnt, it also does this using a linux boot disk, so this rules out an OS issue. I pulled the keyboard, thinking it may need to be reseated, and this is what I found.  Can anyone think why this has happened, the owner states categorically that noone has been in the system. Could this on the very off chance be an OS issue???

[#2]

It isn't a software problem.
Is this under a key?
If so it's either wear or perhaps grit or food got trapped and abraded the plastic membrane.

[#3]

Yes, this bit is under the keys, and it was a bit dirty underneath.  Didnt think food etc could do that to a keyboard ribbon cable..... Looks like somebodys been at it with a screwdriver....