OK - quick workaround / fix (works for me anyway). If you've got one of the maxmem / memsize commands running, get rid of them - I did and now I get at least a bit more time (just had 40 minutes without a crash - at which point the lack of skill/frames/having a life made me switch off.......)
If neither apply - then I'm sorry - just keep on at BIS - after all they ARE supposed to know how to fix this stuff, right??