Crash when saving to VectorPDF

NEV

When saving a LiDAR DEM profile to vectorPDF, the process appears to stall when "Recalculating Projection Grids" at 2% with a "(Not Responding) message" with a grey screen However, it is apparently still working and if I wait ( 3 - 4 minutes) the screen comes back to life, the profile PDF file is saved and can be opened in Illustrator for editing.

Any suggestions?

Thanks

Nev