Semi-Frozen iMac? (folders, apps not responding to clicks)

[extraextra]

I have an Intel iMac, a white one, from late 2006. It's running Tiger, not Leopard.

Today it froze after I quit the internet (firefox). I can still move the BT mouse around (and see the arrow moving), and I can still use the BT keyboard. However, I CAN'T CLICK ON ANYTHING. I can't open any folders, applications, menus - nothing.

So it's just like the applications are frozen. If I hover over the dock, the dock pops up, but I can't click on anything.

I did a PRAM reset, and now I don't know what else to do.

I am using a custom icon set like this, but I've had it for awhile. All that required me to do was copy and paste a picture into the 'get info' part of the application, so I'm not sure if this is causing the problem!

Any help please!

 

[extraextra]

Okay - I've read up on this. (The search function wasn't working earlier, apologies.)

It seems to be a bigger issue with the new 24" iMacs. I have a 17" white Intel iMac with a ATI Radeon X1600 and 1GB of RAM.

I guess the only solutions are to either wait it out and hope that it unfreezes, or take it to Apple, huh?