Q:

Opening ArcCatalog to FGDB causes application to fall over

I have some python scripts I have written to create a lot of objects.   I write these, in code, to a couple of FGDB's.   If I happen to open ArcCatalog in one of these FGDB's, the application falls over, saying it cannot gain a lock on it. 
Is there a way to stop it happening? 

arcgisscripting. ExecuteError: ERROR 000464: Cannot get exclusive
  schema lock.   Either being edited or in use by another application. 

A:

not stock behavior. 
Mine works fine (if not a bit slow). 
The lock means that there is an instance (possibly an arcmap process) that didn't get stopped. 
Check your task manager process tab. 
Also it could be that arcgiscachemgr.exe has it.   
If all that isn't where the problem lies... you might try creating a blank fgdb and step into it from there.