Occasionally when I install .otf font files, XP can't tell the roman from the italic. This would be for two .otf files with the same "base name" or whatever with one called "roman" and the other "italic". I see two entries in the font directory, in word processor pulldowns, font browser programs, etc. But when I click one or the other, what is loaded and displayed appears to be the file I installed first. I.e. if I installed the Roman then the italic, after both are installed when I click either, only the Roman is displayed. If I then uninstall the Roman, and then click the italic file, the italic file is then correctly displayed. I've also seen similar problems previously distinguishing bold from book, etc. This isn't consistent behavior, but occurs only with certain fonts. After installation, I can also click on the problem files still compressed inside of the original zip files and the same thing happens. It's like when one of the files is loaded, XP automatically redirects it to the other. If I swap the order of installation for the two problem files, the other file is displayed. There are no problems with the glyphs themselves, as under the right circumstances they can display correctly, but just not when both are installed.
Any suggestions? Are there any tweaks to the otf files or the registry that can be performed to keep XP from confusing them?