Q: 2009 macbook pro touch pad glitchy

Option click the battery icon in the menu bar to make sure that the condition

of the battery is "Normal".

Clean the trackpad with a dry microfiber cloth.

For more on this:

http://support.apple.com/kb/TS1449

Best.

To supplement Domink23's advice, sometimes a very through cleaning of the trackpad will get it to work properly.

Ciao.

Something similar happens in my case as well, but I don't think it's a matter of just cleaning the touchpad because it starts working Ok if I restarted my MacBook Pro. Plus it happens when I'm using Chrome only.