DS Visualizer crashes under limited user account on WinXP

If I run DS Visualizer 1.7 or 2.0 as a limited user it crashes whenever I try open a structure file or open a new 3D window. Sometimes it crashes randomly while I am browsing through the Preferences window. It never happens to sequence and script windows and files.

In C:\Documents and Settings\user\Application Data\Accelrys\DS Visualizer\2.0\Diagnostics there is a text file, which has the following lines dumped upon each crash:

****************** Application started 2008-Feb-19 22:33:18 ******************

File WindowsFileAssociationManager.cpp:401
Error: Failed to unregister extension.
Access is denied.

Does anyone know how to fix it?