Google Calendar events not syncing with winmo calendar

[Guest skinnny]

The setup:

I have a Samsung Omnia running winmo 6.1.

I have chosen to sync only the calendar (ie I am not syncing contacts).

I have only one google calendar.

I am syncing manually.

Most of my calendar events are in the future (I have only just started using Google Calendar).... and I have configured my phone to sync "all" past events.

I have not imported any events from another calendar system and I have no recurring events in either (Google or winmo) calendar system.

The problem:

When I perform a sync through ActiveSync, new events on the phone are synced to google calendar, but events on google calendar are not synced to the phone.

The phone gives no error messages and shows the last successful sync time as the lastest time.

I'm on T-Mobile in the UK... but I don't think my problem has anything to do with carrier because it also occurs when attempting to sync over wifi.

I have posted about this problem on the Google Mobile Help forums, but have yet to hear anything helpful.

Anyone know what might be causing the problem?

TIA!