Fact selection dialog, shows 3 lines on some browsers, and 10+ on others.

Issue

When adding a condition to a rule, the dialogue box that pops up only shows four lines on Firefox 5. The same dialogue box shows many lines, using all the vertical space available.
The dialogue box on Firefox 5 is too small.

It causes useablity issues here especially when you have 50+ facts to select with a three line selector, the scroll bar is hard to select and it scrolls too fast.