What version of VisualWebGUI are we talking about ?
I tried reproducing what you describe in 6.2.4 and 6.3.0 and was unable to. Working both in IE7 and FF3.
Best way to describe those problems is by creating a most minimal application that demonstrates the problem(s) and then send your application to support [at] visualwebgui [dot] com with a link to this forum thread, along with some description about how to reproduce the problem.
Please also clean the solution before compressing it and reply to this post after sending, so we will know to check for your support request.
In this case, I think it would help to receive an image of the effect you are reporting as error, just in case we are unable to reproduce.