For me, the reverse is true: if I also sync contacts it fails. This worked OK until last month, go figure....

I tried SyncEvolution but that synced 75 contacts of my 400, throwing the rest off my n900 (thanks alot crap)

Apart from that: I have my country and language settings differently, because I want it to know I'm in Belgium, but I do like the interface in English... But this never was a problem for calendar sync.