The current version is 3.10.101 (this is the enhanced version from Object Desktop).
I believe the shareware version is 3.1x, though it is now a 30 or 60 day shareware version - so updating would place you in a time frame of use if you are using the free route.
I would suggest using the following procedure to attempt clearing the issue:
1 - Start IconPackager > Tools menu > click "Restore all Icons" > click "Yes" in pop-up to confirm > click the "OK" button in IconPackager panel to complete procedure.
2 - Repeat step #1 for the "Rebuild Icon Cache" option in the Tools menu.
3 - Do a search for "iprepair.dll" (without the quotation marks), and make sure to use the advanced options in the search dialog to include hidden files and folders. You may find this ".dll" file in both the IconPackager sub-directory, and in the "Temp\SDCentral\Base" folder if you use Stardock Central.
4 - Rename any "iprepair.dll" file found to "iprepair_old.dll" (again, without the quotation marks)
5 - Reboot the computer and try to apply whatever theme you were using, and then use "Icon Packager\Icons and Cursors category\Folders button\My Music folder\Change Icon\Apply" method to test functionality.
That would do it with the current version, and as I recall - the procedure is the same with the version number you are running. 
If the ".dll" message appears again for some reason, make sure to note the complete text in the message so someone can help you. 
