When I go to my cart this is now all that I see in the browser:
1034 Incorrect key file for table 'zen_whos_online'; try to repair it
in:
[delete from zen_whos_online where time_last_click < '1173101780']

If I check the "whos online" in the admin I get this:
1034 Incorrect key file for table 'zen_whos_online'; try to repair it
in:
[delete from zen_whos_online where time_last_click < '1173101931' or (time_entry=time_last_click and time_last_click < '1173102591')]
If you were entering information, press the BACK button in your browser and re-check the information you had entered to be sure you left no blank fields.

Can anyone help me repair this and also (maybe more important) why did this happen? I have not done anything to the working shopping cart in days and this just came out of nowhere.
Thanks,
Jesse