Thanks!
yah I totally agree with the conservatism. My max is actually on the order of 130ipm. I have tried to alleviate this problem with 50 ipm, which would be ~38%, and I still have problems with this one particular oddball scenario. In fact, if I turn OFF backlash comp I can run this section of code at 120 ipm no problem, did it earlier today just for demonstration sake.
I have milled dozens of projects, with lots of rapid changing of mill direction and lots of rapids. This may be the first time I've ever encountered a rapid move that involved such a short move on one axis. I am really starting to wonder if this little phantom un-programmed lurch is happening, but when played out at my normal move speeds is forcing my motors into a frequency well above what they could reasonably step. Then, once they are out of phase as it were, its just a good old fashioned stall :\
For all I know, when I'm commanding a G0 move, the backlash comp might be signaling a lurch at 200 ipm... just not sure yet. That woudl be incredibly odd, but I'm trying to find a scenario wherein this problem only creeps in under these very particular circumstances, and this is where that path has led so far.