Watertight snaps

 From:  fraser
3345.1 
I'm having problems modelling a watertight solid on a 12 x 12 inch grid with snap to grid set to .5 inch. Some of my curves seem to miss the intersection unless I turn off object snapping first. Any suggestions or tips? f

ps The December beta performed fine on my MacBook Pro under Fusion 3.02

EDITED: 24 Feb 2010 by FRASER