Where did the profile come from? Also did colorsync give any kind of error? Sorry if I'm a little vague, but I don't do much of this on a Mac, mostly I work with Windows, and all my color tools run on Windows.
It is possible that the name is just not right. There are two names for a profile. One is the file name, and is the one that you normally see. The other is the internal name, and this is what Photoshop will display. If the internal names is something other than what you expect, you'll never find the profile.
Now here is the good news, you can edit the internal name in Colorsync. I'm not going to try and tell you how to do this, because I haven't ever done this, but I know it can be done. Try opening it in Colorsync and changing the internal name to something that you can remember.
If it was a profile that you downloaded from a paper vendor, I could check it if you have problems with Colorsync.