W960i problem

I purchase this phone 3 months ago and I recently started getting a problem with the screen. Sometime the touchscreen won't work I I'll have to restart the phone and then it will start working again. I recently did a factory reset and it worked for a week without problems and now it jus started back again touch screen working now and then.
How do I fix this problem? also could this be some sort of software problem?

It could well be a firmware problem yes, but to be honest, it would be much easier just to get a replacement phone. THe phone should still be under a standard warranty, so just return it to where you got it, show them the fault and they should either fix it free of charge, or give you a replacement phone .