I have created a ticket for this as well, but I thought I would submit here as well and see if anyone has seen this behavior.
I am having an issue with the RadGrid and partial postbacks. For the partial postbacks I am using the RadScriptManager, RadAjaxManager, and the RadAjaxLoadingPanel.
The scenario is pretty basic. I click a button, some data is retrieved, and bound to the grid. The issue that is happening is the data retrieval process is pretty lengthy (upwards of 15-30 seconds). When the partial postback returns the grid has all of the data, but the styling for filtering, sorting, etc is all messed up.
A couple troubleshooting steps I have taken is to hard code the data being returned so it is faster. That actually fixes the problem and the grid comes back styled perfectly, so I am thinking it has to be the time to return is causing issues. I did find another person on the forum who described possibly a similar problem, and the recommendation was to increase the ScriptManager.AsyncPostBackTimeout value, which I have done, and that did not help.
Any assistance would be greatly appreciated. I am under the gun to get this done asap! Thanks