The callstack showed that during the construction of a window an "Out of system resources" occurred. The OS cannot create a window at that particular time. We've seen the same error in other application also, like outlook and starteam. When it happens to us often a lot of applications are started at the same time and windows tries to serve all applications. QA found the same error on virtual machines.
When investigating this issue the amount of GDI handles allocated by other processes is a good indication if this error might occur. The GDI handles can be found in taskmanager. Probably you have to select the GDI, because by default it is not selected.