Here's my setup: I'm on a Mac (no Microsoft Outlook...too limiting), I created a "dummy" gmail account for just my contacts and calendar to set up as my one exchange account in the N900 as having my main gmail address as the exchange account, with e-mail, contacts and calendar would not sync properly. Others were also having success with this. In other words, one gmail account as exchange with just contacts and calendar and your main e-mail gmail account setup as an imap account. There is currently no iSync possiblility either.

This seemed to work in the beginning. First sync worked, as did subsequent syncs (one way only: to N900) IF I rebooted my device before syncing. Well this slowly stopped working and I'd get the message: "syncronization failed"...repeatedly. I was therefore hopeful that a major update nearly two months after the phone was released would fix this. Nada.

I now get the message: "Exchange server is not responding. Verify that account settings are correct." Perhaps they just changed the language of the error message, or perhaps they've even gone backwards on this. Who knows. Well, somebody knows and they aren't talking.

Surely there is a significant percentage of N900 users with gmail accounts who'd like proper syncing and/or N900 and Mac users. What gives? Why can't this be addressed? Isn't this a basic function?

Don't get me wrong. I love this phone/tablet and all it can do, will do, and should be able to do. But I need this phone/tablet to work properly so I can do my job so I can afford gadgets like this. I have no way of new contacts now, short of entering them both in my computer and the N900 or dragging a vCard over to the N900. Lame. Not to mention the lack of two-way sync.

nuevasync?

I have the same problem. I was very excited about PR1.1 and it just doesn't work. Has anyone else been able to get it to work? Does one need to delete everything and sync from scratch again?

Use nuevasync.... there is a lot of posts here that clarify that google/gmail is not completely exchange compatible

I installed Nuevasync today. Lots of error messages even after the initial sync. Server address not found, communication error etc. I'm running the five day pro trial.

A bigger problem though is that contacts are supposed to be merged, so I have one of each contact that includes im, phone, email and other fields. Merging contacts breaks horribly for me using Nuevasync and all contacts appear to be unmerged after sync. I turned off contact syncing alltogether and use it only for calendars. Nice effort though.

First "full" sync only synced calendar, then subsequent manual sync worked fine. As normal you should not attempt to sync your google email via exchange.

FWIW, I'm coming from a Droid, which had (3) different email clients:

1. Exchange
2. GMail
3. IMAP/POP3

GMail was configured in its own app (IMAP account), which was basically slightly more robust than the native POP3 client. It was not configured with the Exchange specific client, and I only have it working on the 900's "IMAP/POP3" app. (FWIW, its working without issue). GMail app shared some features/settings with the Exchange app, but they were different beasts.

I think that one of the main issues also is that GMail uses "labels" where Exchange uses "folders". As a backup, I have a "bookmark" to my "logged in GMail inbox".

Well I believe I found out, syncing works for me up until the moment when I merge my contacts with my IM contacts (msn-haze, msn-pecan seems broken for me). Then calendar-only sync works, but contacts are broken. After a complete resynchronisation it works again, up until the moment when I decide to merge.
I am still in the evaluation period of this discovery and need a couple more hours/days to find out if the sync won't break at some point if I don't merge anything, but I think I found the reason for the sync to give up after a while.

google sync is working fine for me with no third party software just the standard exchange on the device with the following settings:
server: m.google.com
port: 443
secure: yes
username: ************@gmail.com
password: *************
domain: empty dont put anything
uncheck "sync email" because that doesn't work other than that contacts and calendar is working fine except one thing i found wrong with the having multiple calendars on your account only the main one gets synced..

Mine wasnt working until i do the full resync. Manual sync didnt work, it didnt sync calendar. But after a full resync it did.