Seth,

Perhaps this KB article will assist?
http://support.microsoft.com/default.aspx?scid=kb;[LN];172338


"Seth" wrote in message
...
I am using the API timer functions in an Excel XP
project. I use the timer to refresh information every 1
second on a userform. When the user form initializes I
start the timer, and on terminate I stop the timer.

The problem is that when I return to Excel I am not able
to use the mouse to click on cells or toolbar buttons. I
found that hitting ctrl-O to open the File Open dialog
will "wake" Excel up (I can select cells and click
toolbar buttons again once I close this dialog).

Does anybody know what is going on? I only get this
problem when I use the API timer functions in conjunction
with a UserForm.

Thanks,

Seth