Please can anyone help me as this problem is driving me mad!?  My WLM states it is receiving mail, however when you press "send and receive", it is downloading literally thousands of messages that aren't there and I have to press stop to end this process.  If there are messages to send, it will then send them with no problem.  A few minutes later, when it checks for new messages, the whole process starts up again and it says receiving but is then downloading hundreds and thousands of non-existent messages.  This problem is intermittent and may do it for several hours one day, behave completely the next day, do it for an hour another day, and so on.  I am unable to receive my messages via WLM though until it behaves itself and have to revert to checking emails via my provider, TalkTalk, who categorically refuse to take any blame as state WLM is a 3rd party which they don't support and that it's not a server problem.  I have taken the computer into an IT shop who uninstalled WLM and installed WLM 2012.  This took ages as they had to transfer all my folders over which then caused more agg for me as any folder or email I had deleted over the last 10 plus years transferred back into my account!!!  I am still having to delete old emails and folders that I haven't used in years.  I have since taken the computer back into the shop as this new installation still did the same thing.  They say they resolved a couple of fixes and it came home and behaved for a day but now it's "receiving" mail again that isn't there!  When I press "stop" it then gives me an error -

Unable to send or receive messages for the pop.tiscali.co.uk account. An incorrect password was entered. The next time you send or receive messages, you'll be asked to enter your user name and password for this account.

Server Error: 0x800CCC90
Server Response: -ERR [SYS/PERM] sequence number mapping array overflow
Server: 'pop.tiscali.co.uk'
Windows Live Mail Error ID: 0x800CCC92
Protocol: POP3
Port: 110
Secure(SSL): No

There is nothing wrong with my password!

Please can someone help me on this?  I'd be very grateful.  Please bear in mind that I am NOT highly computer savvy - I'm OK but not that good if you get my drift so any help needs to be in child's terms please!