It is hard to say what could be the problem ... do you have this issue with all your scenes, or only with big and complex projects?
I know that there are some stability issues while working with large scenes or with large volumes that can fire this CUDA error 719 problem (I have seen reports in the forum about this error is other plugins). At least one will be fixed for the next alpha build.
Anyway, do you have a example scene with this problem that you could share with me? This could help to fix the problem.
Computer Graphics Software Developer
Octane plugin development and support: LightWave and Houdini