Question: maple 15 is broken

hi, i am a danish htx student and we use maple for our math lessons, when i started here i installed maple 13 and it has been working fine, but our serial runs out so i had to upgrade to maple 15. when i did i uninstalled the previous maple version and installed the 64 bit maple for my 64 bit windows vista. now when i try to do for instance f(x), the ( and ) breaks maple and all text/numbers vanishes, if i open my previous school homework they look empty aswell. clicking and dragging around with the mouse seems to select "something" though i am unclear what it is. so at the moment i am unable to do any math in school and not even the tech guy here seems to know how to fix it either. so i decided to ask around here in hopes of solving my problem.