I can not directly reproduce what you are seeing.
The other element that certainly will play here is what you have stored in your Inventormateriallibrary.adsklib file.
I did see a ton of duplicate appearances used by various materials that you have defined in your template file.
The duplicates (styles with same name and a number between round brackets) is a known problem that has not been solved by Update1.
What I would do in your case is to save the custom styles that you are happy with and that you want to keep, to the Inventor adsklib library and remove the cached styles in your template file by purging (Manage > Purge). You won't be able to remove these duplicate styles with delete.