(From Kuroi)...
#navColumnTwo {vertical-align:top}

My suggestion is really just a bit more "sticking plaster" and NOT a proper attempt at a fix.

Heed Kuroi's advice.

In the meantime try this: into:-

#navColumnTwo {vertical-align:top}

insert

float: left;

So you get:-


#navColumnTwo {
vertical-align:top;
float:left;}