I was looking in previous posts for someone having a similar problem like I do. Yours sounds a bit alike. I'm on Ubuntu64, using Blender 2.49 and the exporter script for octane. Even if it's made for octane beta 2.2 I'm using it with 2.46 and it works fine for stills so far.

Now I need to render an ...

Thanks for your comments. Theres is a huge roofwindow that worked very good with a sunsky. Can't wait to test it with new features in the beta
By the way, 7 Msamples/sec on this scene, amazing...

Just got my new NVIDIA card and tried octane with one of my previous scenes. It's awesome, great software!