This can happen both when loading Ar4 or browsing in any of the managers.
In the C:\Program Files\AccuRender 4.0 folder you will find a file rpcshell.dll.
Rename it to:rpcshell.xxx
Open AutoCAD
This will keep AccuRender from finding this control and it will substitute the default Windows control for floaing dialogs.
When service release 1 is complete, this problem will problem.will be corrected.