What maintenance do you have applied?
(Press Alt-H,A and look at Update Versions:
If you want to capture that string enter:
javascript:navigator.appMinorVersion
)
More specifically verify what version of urlmon.dll you have.
<title>319792 - Back Navigation on POST Causes Re-POST in Internet Explorer 6</title>
If you are seeing this problem by using Back, instead try launching
new links in their own window (right-click your links to get their menu)
Then instead of having to go back to the original page you can just
close the second window (e.g. by pressing Alt-F4).
HTH
Robert Aldwinckle