This isn't a Vista compatibility problem -- it runs just fine on Vista. The issue is you've set your display to a large fonts or large Dots Per Inch (DPI) setting, and currently BigOven requires the default setting, which is Normal / 96 DPI. This is regardless of whether it's in Vista or XP. In several parts of the program, we have limited screen real estate and large fonts or large DPI's just don't work well. These can be adjusted in the Vista Control Panel (Personalization).
We've logged this as an enhancement request and will see what we can do to rectify it in the future, but for now, just set the fonts back to normal and it shoudl work fine.