Default [Q]Gta 2 on FPse problem

I was playing gta 2 on my Motorola defy and the x key started giving me problem and it's just there. I know this is quite a specific problem but i thought maybe someone else also plays gta here on FPse? not even FPse but in psx4droid the x button started missing, i press x key for 2 minutes then the character just frezes and then i have to release x and then press it again and then release and press it again for a while and then it starts working normally. Is it because of my touchscreen or something? can it be a defect?