No more Triple Posts... I promise...
This may be helpful for some people (unless there is a fix with the MIR software)
I have my iTunes library on an external drive, and MIR was not functioning with it.
MIR takes your AAC/m4a file (that you drag into it), converts it into an m4r file with edited meta data, sends it to iTunes, where it is put into the Ringtone Column (left side of the iTunes UI) and the Ringtone Folder, then it renames the file to m4a so it functions in your iPhone.
If you have an external drive storing your music there is a problem between when it adds the meta data and sending it to iTUNES (probably a simple fix, but it wasn't fixed when I started typing this message). Here is how I did a work around if anybody is in the same boat.
I originally did it with two computers, but I think one would have been faster. Try this, if it doesn't work, some assumptions didn't work.
Step 1. Go into iTunes and set your library location to your music folder on your system drive (rather than your external).
Step 2. Drag your desired (already edited) AAC/m4a files (ringtones) into MIR. The script will now work, but you need to get them on your external drive.
Step 3. Open your Rintones folders on both HDs (system and external). Drag the ringtones from system drive to the external. If it copy's rather than just relocating the files, you will need to delete the ringtones from your system HD.
Step 4. Open iTunes (if you closed it for some reason) and change the iTunes library location back to your external drive.
Step 5. Click on the Ringtones to listen to them in iTunes. If they don't play automatically, you will be asked if you want to "FIND" them. Follow the prompts, and find each Ringtone in your iTunes/Ringtone folder on your external drive.
Step 6. Go to the Ringtones TAB and set up your Ringtones options so you are syncing the ringtones you want.
Step 7. Sync your iPHONE, and you will be able to use ringtones.
Somebody could have probably said this much more clearly than me. Since I am usually trying to explain things to my grandmother who is in her 80s, it is done over the phone, and never done in this few steps.