.Mac sync errors

[LuKreme]

It seems like everytime my Mac tries to sync with .Mac I get the  
following error:

"Invalid response received from .Mac.  Could not complete  
synchronization - please try again later"

The trouble is, when it does this, it still updates the 'last  
synched' time, so I have no idea if the computer has ever  
successfully synched up (and by 'ever' I men in the last 2 months or  
so).

I have it set to synch 'Automatically', but I've also tried manually.  
Each time I get:

You are about to sync the following information with .Mac

    * Mail Accounts
    * Keychains
    * Mail Rules, Signatures, and Smart Mailboxes

What would you like to do for the first sync?

  [ Merge data on this computer and .Mac ]

And then anohter dialog, much the same, for Contacts.

After it tries to sync, I get the error.

Do I need to just replace the data on .Mac? Trouble is, I'm not sure  
that there isn't data on .Mac that I will lose without a successful  
merge.

-- 
The fact that Bob and John are married does nothing to diminish  
anyone else’s marriage any more than a black woman marrying a white  
man, a Jew marrying a Catholic, or an ugly Lyle marrying a Pretty  
Woman. <http://www.ix.lt/?as89>