Do you have sweaty hands? It's one of the few causes of that because I have sweaty hands and my keyboard will occasionally go haywire. Another problem could be low RAM so please check how much free RAM you have.
Microsoft Certified Professional
Sony Ericsson Xperia Arc S(LT18i) - Unlocked BL(CM11) -> INO 2(4.2.2)
Sony PS VITA PCHJ10001(初音ミク Project Diva F Limited Edition)
1.69 - > 1.80 - > 1.81 - > 2.00 - > 2.02 - > 2.11 - > 2.12 -> 2.61 -> 3.00 -> 3.01
Sony PSP - 2006(Original replaced with 2001 MOBO)
3.60 OFW - > 5.00 M33 -> 5.50 Gen D3 -> 6.60 PRO C