Irradiance maps (prepass) corrupt when using backburner

[cgrant3d]

Been pulling my hair out over this one.

I'm using the irradiance map prepass method for animated GI. Turns out that if I render locally they come out at 1.5MB and over backburner they're 1.4MB... The backburner ones are corrupt (can't view properly with imap viewer nor work when changing to Animation (rendering). The local ones are viewable and work fine... I am going to try and reproduce from a blank file.

Here is a link to a zip that contains both the corrupt irradiance map and the good one.
https://docs.google.com/leaf?id=0Bx-...ut=list&num=50

VRay 1.5SP5 ... 3ds Max 2010 with connectivity extension & 2010.06.08 hotfix (BB 2011 compatibility)... Win 7 64.

[cgrant3d]

Hmm. Even more frustrating is I can't get it to repro with a basic file but I can do it over and over and over with my production file.

Corrupt irradiance maps with backburner. Flawless rendering locally. File destination doesn't make a difference - I've tried saving locally or over the network... This one has me stumped.

[cgrant3d]

I've managed to narrow down the bug - though not with BB as before. Using the "prepass" IR mode if I render local with "don't render final image" checked I'll get a good IR map but if I don't uncheck it I'll get a corrupt map.

Just did another test and the good map is 5,224KB and the corrupt map is 5,189KB. They're exactly the same file, rendered locally but one had "don't render final image" checked and one didn't.