[plt-scheme] annoying hanging behavior when saving files on DrScheme version 3.99.0.13-svn26feb2008, english

In DrScheme version 3.99.0.13-svn26feb2008, english,
when I type anything into the Definitions window,
click on the "Save" button, and then try to navigate
through the folder tree to a folder to save the file,
DrScheme hangs at a random point in the folder
navigation process for about seven to eighteen
seconds.

Exactly where DrScheme hangs seems to be random, but
this usually happens within about five seconds of
pressing the "Save" button and then clicking on the
down-arrow next to the folder name at the top of the
"Select a file" dialog box.

The same hanging behavior occurs randomly whenever I
try to right-click on a file or folder to rename it or
to copy the filename in this dialog box as well.

This hanging behavior sometimes happens multiple times
when navigating through a deep folder, or when
renaming multiple files/folders, in that dialog box.

I am using DrScheme on Windows XP Professional Service
Pack 2 (at work).  I tried rebooting my PC and
restarting DrScheme, but the same general phenomenon
still recurs.

The same phenomenon has also happened with DrScheme
v371 as well.

Could somebody please tell me how to fix this problem?

Benjamin L. Russell