anybody see anything like this while retopo-ing inside zbrush 3.5r3 on win7/64bit?

i started noticing it occasionally (usually while zooming in or out), and soon it became nearly impossible to re-topo. not only do i see this type of thing more often than not, new creation points have started start floating way off the mesh (if they take at all).
tia,
-j

- it’s more precise when connecting and isn’t glitching.