Stress testing jit.gl.sketch

Hello everybody,

I put up a very simple patch which roughly simulates the real situation I wish to achieve (tracking a point in space and drawing a line). Here it is:

Now, I'm sending pseudo-random values to jit.gl.sketch at 30 hz interval, simulating the behaviour of a tracking system. The values are given to jit.gl.sketch as strokepoints.
The first issue is: if I let the patch go, the framerate drops in less than 30 seconds, then Max crashes. Maybe too many strokepoints?
The second issue is: if I let the patch go for a while (about 15 secs.), and then I send the "endstroke" message, Max crashes immediately.

Is there anything I can do (apart from trying to reduce the random values' frequency)?

System Info:
Max 6.1.2 on MBP late 2009 (NVIDIA GeForce 9600M GT), Mac OS X 10.6.8