Ladies and Gentlemen with flashing problems should go here
http://forum.ppcgeeks.com/showthread.php?t=51508 for a possible soln.. I experienced this several months ago... and it seemd to work... I honestly think it is related to backup type software...... I think the key for me was formatting my internal storage.... I also tried turning off the synconizing files in active sync....
Trust me this isnt a permanent problem you have not been striken by the ROM flashing gods (or should it be Official Carrier Rom Gods?).... anycase good luck
Cheers,