Dell Inspiron 1501 Touchpad problems

I upgraded my Dell laptop to Windows 7 32 bit from Vista 3 weeks ago. I had no problems with the touchpad before the upgrade or after until 3 days ago. I started the laptop up and the touchpad was frozen.

Searching for answers, I tried the following:

• Get driver from Dell: only thing is, Dell doesn't have Inspiron 1501 touchpad drivers for Win 7. I got the Vista one and installed it. Didn't help.
• Checked to see if a Function key disables the touchpad. No key like that exists.

I did a Safe Mode reboot, tried no AC adapter, nothing worked. Suddenly, after just another shutdown and start up, it worked again. For a day. Just as suddenly, it stopped working after a sleep mode. Nothing I tried such as reboots etc. brought it back. For 2 days it stayed that way until again it suddenly came back. Last night, it stopped working twice and then suddenly came back. Sometimes it would work in safe mode, some times it wouldn't.

I did not install any software right before this began. I didn't touch the hardware of the touchpad, I didn't knock out the connection. It worked fine for weeks after the Win 7 install, so I don't think that can be it.

Any ideas? Thanks!