Some months back I setup OMA on the server (SBS2003, all service packs/updates - having just typed that, have I discovered my issue?)
It worked fine until 2 weeks back, now the mobile device (XDA Exec / Orange SPV M5000) chucks out the "Server Busy" error 0x85010017 on syncronisation.
I get the same error on my Orange SPV M500 (it was used initially to test/setup OMA).
OWA/OMA works fine from the web with no issues.
TIA - Bill.
PS; I hate mobile Activesync, it just stops working when it feels like and then takes days to resolve.