So, given that this is such a headache for many folks, is there a workaround? Like, in XSI you can "Freeze" an object or scene - it dumps everything you've done up until that moment - you'd better REALLY be sure! Is there any manual way to "dump" your history - or whatever it is that's causing the holdup or leak? Dump your history (like all your test renders as an example) before you hit "render" to free up as much resources as possible?