calendar going bonkers

help!! the default widget calendar looks great in IE, but monday and wednesday cells go super huge in firefox, pushing the alignment way off.

i have tried removing all css edits and have made no changes at all to the source codes (tried editing htem also, but later re-loaded the originals).

see here:
http://makisquarepatch.com/wordpress

any ideas how to solve this? thanks 🙂