some odd behavior

[ccwerks]

Im trying to cut some plain old circles out of 26 mm thick carbon fiber. Simple 2 d path. as im going through the tool path the machine lingers at -9.5 mm and then plunges to 15.5 mm though its not reflected in the tool path. has anyone else had this issue?
I also reset my computers and the bot.

[ccwerks]

So after a little testing It seems that when tabbing is on is when I have the problem any ideas?