Question : Some users can't access OWA

We have an exchange 2007 server that has been working fine with OWA for a year and a half.  All of a sudden, today a few users started to have some weird issues.  Their AD accounts would get locked, and they couldn't access their computers.  Both users were receiving emails on their iPhone via OWA.  This could be a coincidence.  Anyway,  I think their accounts were getting locked by their phones somehow.  After resetting their passwords, and unlocking their AD accounts, they were able to get back into their computers, but their iPhones would just keep asking for a password, no matter how many times they put it in.

So, the weird thing is OWA is working just fine for most users, as well as active sync.  I get email on my windows mobile phone no problem.  I can go to our OWA web portal and log in just fine.  But if I try to log in as these two users, it just says their user name and password are incorrect.  I have tried this COUNTLESS times, and I am POSITIVE we are using the correct passwords.  So there is some really funky issue between AD passwords, OWA, and the iPhone that is causing problems.

Does anyone have any ideas on this one?

Answer : Some users can't access OWA

Thanks for your responses.  I think I found the problem, and it seems to be completely unrelated to OWA, Exchange, or iPhone.  The problem seems to be with my AD servers replicating.  What I had to do to fix this problem was go onto one AD GC server, reset the password/unlock the account.  Then change the domain controller to another AD GC server, reset the password/unlock the account again.  I seems like my GC servers are not replicating.  I think this might also be true with my group policies.  What a mess.  Anyway, I'll start going down that road.  The OWA is working fine for those two users after resetting their passwords on all domain controllers.