its because of the auto complete built into the new msn.
to disable it u can use Stuffplug-NG (has lots of other features, so i suggest this. but it is in beta, so you mite get some problems) or a patch (should get no problems with this)
StuffPlug-NG 0.4.17 (On-the-fly compression!)
or a patch
link will be addin in a min (i can't find it)
http://mess.be/pafiledb/pafiledb.php?action=download&id=536 (only for 6.2.0133)
[edit]
any1 know where the patch for 6.2.0137 is ?
http://mess.be/pafiledb/pafiledb.php?action=download&id=546
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