Did you already check the stacksize of Devs/DosDrivers/CD0 as suggested above?
You could also try to install 'MinStack 10000' and 'MemTrailer 96' in your startup-sequence.
Maybe one of them can help you to avoid memory trashings.
http://aminet.net/search?query=minstack
http://aminet.net/search?query=memtrailer
Put them both below SetPatch