I have been unable to use PSP on Vista because of a similar display problem. It
may be the same problem as mentioned in this thread, but I didn't see this
exactly.
Halfway down a file (in my case a PHP file) the display would not show the
characters in the same place as the cursor.
When I would move the cursor with the arrow keys from the beginning of the line,
the PHP/HTML tag would highlight in the white space before it reached where the
tag was showing. The offset was as much as 10 characters at times. Needless to
say, this made it impossible to edit a PHP file with PSPad.
When I would try to delete white space at the beginning of the line with lots of
white space before the tag, the displayed characters further over the line would
jump erratically each time I pressed the delete key. It was if it I was deleting
tabs instead of spaces, but sometimes the characters would shift right on the
line after pressing the Delete key.
This thread gave me a big start in finding a solution. The discussion of the
Menu View / Special chars ) solution started me on the right direction. While
changing the View Special Characters didn't fix the problem, *View OEM
Characters* DID!
PSPad now works perfectly. Even though I don't know why, I can now use PSPad
again on Vista to edit PHP files. Great!!!

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