I saw your thread here an have a question.

I use a Lodestar X2 too for guiding, and a Moravian G2 8300 colour for imaging.
I have the problem that the lodestar keeps timing out all of the time.
My only solution to this atm is to set the lodestar on binning 2x2, this way it works fine.

Could you explain a bit clearer for me, what exactly and where you changed the buffersize?

Maybe this would work for me too.