TI Home 2010 Mount and UnMount probs

Many times I can't mount images and get the message:
"Cannot assign a drive letter to a partition from the backup archive"

At first I thought this was maybe a problem with trying to mount a TIH9 tib under TI 2010, or maybe a file corruption, but I have also discovered that after I mounted and then unmounted a tib created with 2010 when I tried to mount it again I got the same message. Not very helpful.

Meanwhile the one TI9 image I did get to mount claims not to be mounted (in the GUI wizard no mounted images shown) so I can't unmount, well not from the GUI, I see UnMount as a context menu option though. I did previously unmount a different image from the context menu, does TI have a problem with two mounted images perhaps?

This is also odd as I did go into the unmount wizard earlier because having mounted this TI9 image I couldn't remember which file I had actually mounted and I thought the filename might be shown there. The filename wasn't shown (is there anyway to get the names of mounted images?) but I did see that something was mounted.

Another problem I found was I wanted to mount a differential image that is not the last differential in the set (ie I want to see the files as they existed at a backup after the initial full backup but before the last differential one). Having selected the appropriate differential file I was then presented with a image "name" that showed only the LAST differential set. Maybe this piece of insanity is because I have one directory that has the base image and some early differential files and another with the base set and just the latest differential. Who knows, this whole program seems to be trying to be too clever for its own good.

So, anyone know what the trick is to get TI 2010 to reliably mount and unmount single and multiple images, and be able to selectively mount specific differential versions? And also how do I check what image is actually associated with a mount drive letter. Additionally, I see no easy way to view the comments I use, is there some trick to seeing them? This is all too time-consuming for me.