Thanks for contacting us.
Could you please give us some more information about the issue you experience? A sample application that manages to reproduce this behavior would be of a great help since I will be able to thoroughly investigate the case. Please note that you will have to open a support ticket in order to be able to attach the project.
However, with the last release (Q1 2009 SP1) we have introduced some major performance improvements within RadForm and thus I advise you to install this version of our product and try it out.
I hope this will help.
Do not hesitate to write back if you have further questions.
the Telerik team