Solved: I was doing output to a text box and i had code that said (if textBox.length > 400 then.... erase first half, keep second half (ie. TextBox.text = Mid(textbox.text,200) ) but...i erased it and it's working fine now...I'm guessing it was trying to write to the textbox while the mid() function was still trying to split it...not sure, but I removed (well... TextBox.Clear() instead) and it works fine now.
sry..should have wrote more specific code..i actually use
Do While LocalPlayer.Rotation - 0.1 > targetRot
'do nothing
Loop
or +0.1 if I'm turning the opposite direction
o, and it's in radians atm, 0.1 seems to work well