Twist on problems with Time Machine reconnection after a logic board replacement.

Hi. I've been trying to find a solution to this in these communities and elsewhere on the Web, including Pondini's website, but seem to be stuck. I just had the logic board replaced on this MacBook Pro running 10.6.8 this week. I tried to reconnect to my 2TB Time Capsule, somewhere under a year old, and got the expected "re-use or new backup" dialog. I chose re-use, as I would naturally like to just carry on from where things were, but the sparsebundle didn't mount properly; something about "resource in use" or "volume already mounted", I unfortunately don't recall exactly which error it was.

Now, I don't get that dialog any more, and I still can't get the connection to that sparsebundle. I'm able to mount it manually, but not via Time Machine.

There's plenty of space on that Time Capsule - about 1.72TB free. My wife's MacBook is still backing up to it without difficulty (we just replaced her warped battery to allow her trackpad button to work again, but that's another story).

I tried a Terminal hack with replacing the MAC, but apparently just can't find the old MAC, for which I feel quite silly. I was all set to use the tmutil inheritbackup command but then realized that it didn't exist until 10.7.0; I don't know that upgrading to 10.8.0 while trying to sort this out is the right plan, but I suppose it's a possibility.

Any ideas how to get this recalcitrant sparsebundle up and running again? I'm sure I could just delete it and start over, but the thought of dumping all that data makes me a tad nervous.

Thanks in advance!