Cannot use left mouse click in Classic Mode (Mac OS 10.4.11)

[ltpitt]

Hi all,

I installed Mac OS 9 in a folder copying it in target mode from a working iMac into my eMac.

I can start the classic mode successfully but when an application starts I cannot click on buttons.

The mouse moves just fine but click does nothing...
If I press enter then the selected button is pressed and I see that the application is not hang and works as expected but...
No mouse left click O_O

What can I try?

Thanks.