Unfortunately we haven't seen nor we have received any reports of this issue. Also we cannot reproduce it based on the information you sent and this is why I wanted to ask you if you can give us more details about your scenario.
If you can try to isolate the issue that would be very helpful as it will help us narrow down the cause and help you get over it. This is why I wanted to ask you to try isolating the steps that allow you to reproduce the problem in a written list. Also you said that issue only appears after another telerik controls heavy user control is shown, but often there are only 2 or 3 controls that are directly involved with a given problem.
Can you please try to determine which are the controls that are not related to your issue. We suggest you to use the ‘remove and try’ approach when it is hard for you to determine what is causing the problem. This means that you should remove parts of the code and check if the issue reproduces without it until you find the cause.
Thank you in advance for your cooperation.
the Telerik team
Explore the entire Telerik portfolio by downloading the Ultimate Collection trial package. Get it now >>