Here's what Mark/Space said about NOW & Missing Lync:

NOW Software Conduits:
Some users may successfully sync using the 5.1 versions of the NOW conduits. However, others may experience problems. Mark/Space is working with NOW to determine if this issue can be resolved. In the meantime, Mark/Space cannot support use of the NOW conduits with The Missing Sync for Palm OS.

Any other ideas or work-arounds for syncing problems?