"Exchange 2007 (Offline)"

Question

I've been reading several threads but haven't found this problem yet.
I'm one of about a half dozen Mac users in a Windows environment. They updated our e-mail system to Exchange 2007 about a week before Snow Leopard came out, and after a harrowing week with Entourage, we've all been upgraded and are back on the Apple Mail App, with iCal, Address book etc.
However, of all of us, I'm the only one having this problem:
My Exchange connection keeps going offline.
Odd times
No discernible pattern
Doesn't seem to be connected to a specific action
I get the triangle with the "!" in it and I no longer receive, nor can I send, any e-mails.
The only way to get it back online is to delete the entire account, reboot the computer (much faster with Snow Leopard...) and recreate it. Works great for an hour (?) maybe less. And then without warning, goes off line again.
Trying to go online with the accounts doesn't work.
I've done several things to try to solve it, or even make it happen on purpose to see if there's something triggering it with no luck.
1. Deleted all other e-mail accounts thinking that they might be conflicting. (doesn't matter - one colleague has several accounts, all working fine)
2. I had recently set up Time Machine for the first time. I thought that might be creating the problem, but I had them both running (back up and e-mail) and everything was working - only later did Exchange cut out.
3. I even thought that maybe logging into an online google account might have triggered it, but after testing it didn't do anything.
4. Turned off synch with Mobile Me. No difference.
5. Thought about it conflicting with a third party software, but I don't have that many, and another of my colleagues is a third party fiend, and loads any and all free ware he can find, and has had no problems.
I realize this is all new territory - but thought I'd post in case some one has anticipated this problem, or has already come up with a solution.
Thanks

Answer 1

Problem solved. Here's how:
We had to add our mail server IP address and internal server to the bottom of the "hosts" file in the following directory:
/Private/etc/hosts
At the bottom of the file - below the "localhost" information.
Add the IP address and the internal server address. (you'll need to get that information from your tech people). Like this:
#.#.#.# mail.company.com
You'll need admin access to edit/save the "hosts" file. I had a problem doing that using the default Text Editor, but I was able to use BBEdit to find and open hidden files, and all I had to do was enter my password to save it.
After a reboot, I haven't had a problem all day. Tried both wireless and direct connection.
Hope this helps those that are still having problems.
PS - My tech guy wanted it known that it was a "PC" person who solved the problem for me. (Groan - Throughout this process he would always end the conversations with: "You should just get a PC!") He said that Windows used to have something called an "LM Host file" that was similar or the same as the "hosts" file we used to fix the problem. I got that far in his explanation before he started to sound like an adult from a Peanuts cartoon.