I would say, this might be caused by the same function like the bug in the thread you found (http://forum.pspad.com/read.php?4,43307,43342#msg-43342) However, your sample text works well for me (XPh, Czech) - probably under Vista, there are yet another issues, which haven't been resolved yet.
As a workaround, you can set some highlighter other than txt - and you get the save dialog with New..., then the file extension might need to be adjusted. -- <http://forum.pspad.com/read.php?4,44179,44180> PSPad freeware editor http://www.pspad.com
