Do you have a resolution to this ? I use a Verizon Treo 650, with Missing Sync - and despite some early issues with my not understanding how to set it up, I am now relatively pleased with the way it works.
I have no issues with the way it syncs iCal, Tasks, Vindigo and a few other add-ons.
I do have some issues with the way it syncs fields in Address Book, and I wish there was a way to "map" specific fields from my Address Book to the fields on the Treo, but once I figured oout the limitations, it is OK (I'd say it's about 80% on this one).
Oh yeah - one small annoyance on iCal. I travel a lot and no matter how I enter events on iCal, they somehow end up being added to the Treo in the "Los Angeles" time zone (where I live).
When I'm home, everything is OK, but when I land in Chicago (for example) and the Treo takes it's time from the local network, all my appoints jump to a different time becuase the Treo thinks I still want to meet the client at "4pm Los Angeles time." I enter the times as "local" where ever I'm going to be -
So, on the plane, as I'm taxiing to the terminal., I open each calendar event on the Treo and set it to "no Time Zone" and everything is fine.
This was a HUGE problem for about a week until i figured it out. The Missing Sync folks were actually pretty helpful through it all.