Photoshop CS3 Problem >.<

Today i wanted to do something for my work so i finally opened my Photoshop CS3 i got for my Mac.
There is one weird thing happening....
When i select a tool like magic wand for example, i move my cursor inside the working space area and my cursor it disappears and i cant work . This in not happening with the move tool only, with all other tools i have this problem...
Anyone knows what maybe is the problem? Im sure that i got all the options right and the caps lock off.
(I hope this is the right section for that post)
Thx in advance

is it disapearing or becoming invisible??? i had an issue where my mouse went invisible for a while but can not remember what i did to solve this issue
-chris

ye it was disappearing...
problem solved kinda...
i plug in today my 19" LG display i got on my desktop to see how it is running my mac there..
When i unplugged my monitor from my macbook photoshop decided to work perfectly..Any ideas why ?its a pity to got a 19" display and cant work on it when im home =/

This was a problem with the beta version they had out for a few months, but I haven't heard of it affecting a full version. Check your cursor settings under Preferences is all I can suggest.