MentalRay sattelite problems -Hi Res renders

hi, Im running into problems rendering a single hi-res image (9600x6480)
30% of render I get a MR error:
" PAR 0.n 4982 MB error 021083: no message from slave #1 for three minutes"

if I do a test render at 50% it renders fine.

Things I’ve tried:
I was opening a large scene so removed all shaders and optimized scene.
Eventually I just created a new scene with couple of spheres, disabeled FG and still no go. Dies at 28%

If I drop to 50% res, renders no problem.

Any ideas?
Just pinging to see if anyone else has encountered this problem

Thanks!