I cannot hotsync my treo to my MACbook (10.4.1).

When I try it says "Please delete some data and try Hotsync again." A second message says "unable to initiate HotSync operation due to systems error."

I deleted all calendar data from 2002-2005, and about 30 entries from my contact list. I've had my troe 650 (Cingular/AT&T) for almost 2 years and just started having problems this week. I inserted an expansion card (2G) thinking it would solve the data storage problem and give plenty of room for the device to sync. No luck! Anyone have an idea?