Ext2fsx -- still struggling withthis

A day or two after I installed ext2fsx from here, two (of my eight) Linux OSes (all Ext3) showed up on my desktop and could be read (but not written to).
Then a day or two ago (after maybe a week) they disappeared for no apparent reason.
However, I decided I'd see if I could get them back. So, I went into ExtFSManager and tried to mount each of the two that had previously mounted (Ubuntu / and Ubuntu /home).
They errored on attempted mount and suggested trying disk repair.
So, over to Disk Utility and I tried to repair both and, surprisingly both repaired without errors. Back to ExtFSManager and I was able to mount both without problems. What's more they mounted at boot for at least two more boots.
Flushed with this success, I tried to repair a few (if not all) of the remaining, hitherto unmountable ext3 partitions but all gave the same errors.

Verify and Repair volume “UNTITLED”
e2fsck 1.39 (29-May-2006)
/usr/local/sbin/e2fsck: Resource busy while trying to open /dev/disk0s7
Filesystem mounted or opened exclusively by another program?
Error: Filesystem verify or repair failed.

Even afetr I unmounted the two mounted partitions, I got the same behaviour.
If I tried to mount, despite the repair not working, I got this

Command: Mount
Device: disk0s7
Message: Unknown Error (The filesystem may need repair. Please use Disk Utility to check the filesystem.)
Error: 0xC047

So, it really seems like there is something different about the other 6 unmountable partitions although I really have no idea what it could be.
I posted to the SourceForge forums about this and who knows if I might get the answer here.

Mount ext2/3 in OS X

Apparently, only NTFS file systems will automount in OS X and not at all ext2 or ext3 which is surprising given the Unix common denominator.
Nevertheless, a small package ext2fsx will apparently get over this reluctance. It can be downloaded from here.
As I had all my Music on an ext2 partition on an external drive, I installed ext2fsx on OS X. However, I still couldn't get the ext2 partition (or any of the ext3 partitions) on the usb drive to be recognised.
With that discovery, I gave up, copied the Music to a ntfs partition and used that to get it onto my Mac.
However, today when I booted into OS X, two additional volumes were on the Desktop. These turned out to be the Ubuntu / and /home that I had set up yesterday (both are ext3). Is this because of ext2fsx?
Later on I plugged in the external drive with quite a number of ext3 partitions and one ext2 partition. All of them showed up on the Desktop. This really sounds like ext2fsx is doing something but why the delayed reaction?
There is another mystery, however. On the Mac HD, I have 11 partitions in all. Eight of these are formatted to ext3. So, why are only two showing up on the desktop?