Failed to load control "HBX"

Whenever I try to run pgAdminII I get the message

Runtime error '372':

Failed to load control 'HBX' from HighlightBox.ocx. Your version of
HighlightBox.ocx may
be outdated. Make sure you are using the version of the control that was
provided with
your application.


I get the same results with both 1.1.34 and version 1.1.28.

I am running on Windows 98SE. I used windows installer to install first
version 1.1.34, and then, when that failed to work, version 1.1.28. I
de-installed the previous version before trying the next.

Any suggestions?
--
Thomas Sandford