Reading mail from a CD-R

I've got problems reading email messages from CD-R. Why read mail from
a CD you say?
Well, I like to keep backups of my email throughout the years, so what
I do is simply organize it like I want and burn it to a CD-R, CD-RW or
DVD, and whenever I want to read an old email message (or even search
for something specific) I pop in the CD-R and read it from mozilla,
from an "email account" I've created for that purpose.

Here's a step-by step on how I do it:

1) Once having organized all my email like I want it with folders,
sub-folders and mailboxes, all within a single email account, also
making sure that *ALL* messages are marked "read" (so Mozilla won't try
to write an index file on the CD-R, which of course it can't) I exit
Mozilla (to make sure it doesn't alter any of the files while burning
to the CD) and burn a copy of that account's mail folder from the
Finder desktop.

2) I start Mozilla again, then create a new POP3 email account. It
really doesn't matter what name, POP server etc. I enter here. Just
about anything will do, but for simplicity I like to call the account
"Read from CD" or similar, so I know it's the one for that purpose.

3) Once I've created that account I need to change the path to where
Mozilla will look for its mail. I do this by changing the "Local
directory" path to where the CD/DVD-drive is found (and if the mail is
located inside a folder on that CD I need to include the path to where
the actual messages are found). Here's a screenshot from my setup on
the Windows PC:
http://home.c2i.net/w-460389/windows_mozilla_cd_access.jpg

4) I need to exit Mozilla once again.

5) Making sure the CD-R is inserted in the drive I start Mozilla once
again, and upon entering the mentioned email account ("Read from CD" in
my example) I can navigate through my email just as I would with any
email account, only this time it reads it from a CD (or DVD)!


Now, this has worked perfectly for years on a Windows PC, but having
gotten a Powerbook G4 a couple of months ago I haven't had any success
in making it work there, and I'm clueless as to why not. Especially
since I even use the exact same version of Mozilla (1.7.12) on both
platforms.
I know I've gotten the path right on the Mac as it definitely reads
something (I can open up mail folders/sub-folders), but no messages
show up! What happens when I select a mailbox is that the status-bar in
Mozilla says "Building summary file for MAILBOX NAME" (where "MAILBOX
NAME" is of course the name of the mailbox/mail-folder), then keeps on
forever. No messages are shown even after several minutes of waiting.
In Windows the email messages appear almost instantaneously.

Any ideas what the problem could be? I've tried the exact same mail-CD
on both computers (Windows PC and Mac Powerbook), and both computers
are running Mozilla 1.7.12.
(Here's a screenshot of how the "Local directory" path on the Mac
version looks like when pointing to the DVD-drive:
http://home.c2i.net/w-460389/mac_mozilla_cd_access.jpg).

Also, the CD-R opens up fine on the Mac desktop. I can see all
mailfolders and message files, so the problem seems to have something
to do with Mozilla on the Mac.
I've also tried it with Seamonkey 1.0 on the Mac without any other
results (I installed Seamonkey because I needed a way to quickly mark
all my email messages as read, creating index files etc. instead of
having to press Shift-Command-C for every single folder/sub-folder, and
I recently learnt that there's a hidden function for that in
Seamonkey).