If you had the misfortune to upgrade to the latest version of Mail for Exchange for your Nokia smart-phone, and you are using Google Apps, you might have come across this issue.
The main problem is that Google recommends using the latest version (which is 3.0), while noting that the best supported version is 2.9. On the Nokia site (or rather, the OVI store), the only version available is 3.0. If you upgraded to version 3.0 and were lucky enough to have version 2.9 images around, you need to uninstall version 3.0 (loosing the configuration) and reinstall version 2.9.
The second issue is that there is no direct way to report this issue and get a response from either company. In Google you are led to a forum, with a lot of nice people, none are official Google employees. Google might be listing, and might not. In the OVI store you can comment on an application, but only if you install it directly to you phone from their site. As I downloaded it to my Mac, and I did not feel like re-installing it and un-installing it again, I could not comment.
I am attache the version 2.9 of the SISX files with this post (Nokia, if you have an issue with this, let me know....).
Another option is using the SyncML protocol for contact and calenders, and IMAP for mail.