Pronterface pause/resume to reload filament

I'm having some issues with printrun/pronterface backing the filament all the way out of the extruder when I pause and resume. Specifically it's when I pause to start a new piece of a filament. When I then resume it spins E backwards and I am therefore not able to finish the print. It seems to me that it's doing the old "go to zero" instead of "define this as zero" when it resumes. Is there a way to change this?

I guess when you load the new filament you use the Extrude button to feed it through? That will put the E position out of step with the GCode. i.e. the actual pos is ahead of the GCode, so the next GCode command that specifies E will be less than the actual, so will retract.

If you use M114 to get the current position just after you pause, you can then restore the E position to the expected position before resuming. I guess using G92 Exx.xx or maybe G92 E0 then extrude xx.xx mm.