Mac OS X Calculator.app Problems?
Is your calculator suddenly not doing currency conversions correctly anymore? Do the currencies listed in the currency pulldown menus look funny with lots of blanks on either side?

Then you might experience the same problem i had which has an easy solution:

1. Quit Calculator.app
2. Open Terminal.app
3. Type rm -r ~/Library/Caches/Calculator/

This will clear all Calculator cache files of which one was obviously corrupted in my case.