I'm sorry that it's taken me so long to report back with info on my progress with this fix. Unfortunately, I don't come bearing good news.
Since installing this version of pnd_run.sh, my Pandora takes two to three times longer to start up, and according to the status LEDs it spends a *really* long time thrashing the SD Card in slot one for no apparent reason during this very long boot-up process (I don't know why - I am booting from the NAND). You know how the boot-up progress bar increases in spurts? It happens right after the first part of the bar is filled in, and it stays there thrashing the SD Card for aaaaaaaaaaaages.
Moreover, I've noticed a behaviour that I haven't seen since Hotfix 3! The card in slot one (my main one, and also the one that I happened to install this pnd_run.sh from) is oftentimes not mounted once I get into the OS, and I have to click it out of the Pandora and back in again before it will be mounted - sometimes I will need to do this two or three times before it will finally mount the card. The card itself is fine, and this has only been happening since installing the newer pnd_run.sh.
Last of all, unfortunately, whilst it has reduced the frequency of the "PND could not be mounted" error message, it has not eliminated it. In fact, when it occurs, it is now worse, as it locks up the system much more quickly than it did with a plain Hotfix 5 installation.
All of this is on a Pandora that is booting from NAND, which was updated to Hotfix 5 shortly after the Pandora was received.