Grounding issue on the VGN-Z

So my Z is now starting to show some real issues, at less than (though almost) 2 years of age. Well, it's still under warranty till the day after Christmas this year so if anything, this issue can hopefully be solved (if there is an issue, that is).

So my problem.
My touch pad seems to be 'live'. I've been getting shocks off it. Nothing serious, just a slightly funky, tingly sensation. The thing is it is not all the time. Happens randomly, and I can't get the issue to replicate itself at will (not sure if I want to, incase there is a larger jolt...).

The thing is, is this possible? That is, to get a shock through the semi-non-conductive mouse pad? I would have thought the aluminium palm-rest would be a better candidate, though never felt anything tingly through that, yet...
Granted, I know there are issues with ESD and static electricity build-up. But the tingly sensations do last for less than a second if they do occur, so I'm guessing that is a possiblity.

I do open my Z up for dust clean outs. Though I only go as far as removing the keyboard, not the mid plate. I have checked, and the keyboard is firmly connected to the motherboard via the connection, incase you're wondering. And I use the New Zealand plug with my adapter, which is a 3x prong wall socket plug with 2x being the AC and the third being the ground.

The issue first surfaced back in late June this year, when I sent in my Z to Sony Service for an optics drive replacement. I got it back 4 weeks later (parts delay), started using as usual and that tingly feeling. First I thought it was just me and my head - I'm tired most of the time with university weighing me down. But this has happened a few times, and I know what I feel; the feeling I felt just a few minutes back was the strongest I felt it (though again, nothing painful, just 'funky'), and I'm sure it's not me and my head no more...

So, any one able to state whether it is possible there is a grounding issue causing static / current build-up near / on the mouse pad? Are there also any suggestions as to how one would be able to rectify this issue without taking it into service (ie, a DIY method)?

...though I might take it in as the keyboard AND mousepad has been playing up from time to time recently, though that was since December last year; might as well get the entire keyboard / mousepad system replaced AND the grounding looked at as well..?

Thanks in advance for anyone who helps...

 

Do you by any chance have a network cable plugged in? They can cause grounding issues in rare cases (i've seen a few), try switching the cable type: UTP-> STP (the ones with a shielded/metal connector) or the other way around.

 

Unfortunately, no. I seldom use an ethernet / network CABLE.

Regardless, just tried but don't feel anything.
Note that I can't reproduce this error at will. It just happens, maybe once a day.

Though thanks for the suggestion...