Some background on this :

Our service is designed to service two kinds of device : those that have a multiple calendar capability (e.g the iPhone), and those that don't (e.g. Windows Mobile). The service identifies the device type and behaves accordingly. For devices that only support one calendar, it merges the Google calendars selected for sync onto the device's single calendar.

Now, at present it is our belief that the N900 does not support multiple calendars. "Yes it does!" I hear you say. Well, yes the calendar application on the phone does, but in the context of our service that isn't the important thing. What matters is whether the sync client on the phone will support multiple calendars. There are phones on the market that have a multiple calendar capability, but do not support that feature when syncing with Exchange (e.g. the Palm Pre).

So...since we don't have an N900 here yet to test, I can't be sure that it doesn't do multiple calendars. I'd be happy to work with someone out there who has a) a device and b) some spare time, to test it to be sure. Some Google searching suggests that the developers of the MfE client for Maemo may not have understood how to implement multiple calendar support, and hence the current version of the client doesn't support it (but a future one might).

Hopefully this all makes sense.