Hi Erik,
I think we are on the right track, but we are still missing each other a bit. Whenever you install Norton Ghost 15 (or BESR 2010 I believe) it will add a HIDDEN Generic Mount Control Device in Windows device manager. It's hidden by default, you must click View and then Show Hidden Devices to see it.
When you mount a recovery point image, you will then get a VISABLE "Generic mount point" under the same area of Windows Device Manager, but the Generic Mount Control Device stays hidden unless your clicking "show hidden devices." Now, once you unmount that recovery point then the temporary Genric Mount Point disappears from Windows Device manager and you do NOT end up with any exclamation points, etc.
You can test this on any install of NG15 on either Windows XP or Windows 7 (we didn't test Vista). It's NOT normal behavior from a fresh NG15 install to have this extra exclamation point bearing copy. But we will explain how it occurs below.
Now, take this same (Windows 7 only, Windows XP doesn't have this issue) machine and run the Norton Removal Tool (www.symantec.com/nrt) which according to Norton Support is the BEST way to uninstall Norton Ghost 15. You now should have NO hidden Generic Mount Control Device in Windows Device manager anymore.
Now go ahead and reinstall Norton Ghost 15 (tried the latest version and the original 15.0.0) and after it's installed and you've restarted. Go ahead and check Device manager. You will now see the original Generic Mount Control Device is back and hidden AND unhidden is a new copy of the generic mount control device with an exclamation point. They both point to the same driver files. However, what's interesting is if you check the first driver install date under the details tab in Device manager, you will see that the one WITHOUT the exclamation point (that is hidden) is the original from BEFORE running the Norton Removal Tool. The new version is the one with the exclamation point thats driver installation date matches the reinstallation (post NRT) of Norton Ghost 15.
Hopefully all that makes sense. It's clear as day to me but that' because I've become familiar with the process. Norton Support ended up telling us they have no idea. They kept saying that the Genric Mount Control Device was because a USB device was attached, etc. I finally explained (and demonstrated via a test machine) that this issue can be duplicated on a machine with NO usb devices attached in the whole process (NG15 install, NRT, NG15 reinstall).
The issue we have is that Norton Support told us NRT is the best way to remove NG 15 so we've used it on a handful of machines (when upgrading versions, when replacing destination drives and having a corrupt backup history, etc) and thes machines now have complex jobs and job histories and starting from scratch to set them up would not be convenient, but if this issue can impact the backup process in anyway we'd be willing to. We just can't get a straight answer from Norton Support, they are supposedly going to have the Norton Engineering Team call us tomorrow.
Again, for what it's worth, our backup jobs run and return a succesful result (with the verify option checked) and to answer your newer question we CAN mount them to a drive letter. We have also test restored a few files and they restore "okay." Our only concern is it's not practical to restore the whole PCs and as such, could this issue be causing an underlying problem in the Backup anywhere. I guess it depends on how thourough a check NG does before reporting "Backup successful" ?