What kind of crazy NAV disc do I have?

I've got a Toyota NAV DVD disc that I can't identify. The numbers on it don't quite match up with anything else I've seen reported on the internet, so I'm having a hard time trying to figure out what car/system/Nav gen it's for. Anyone want to take a guess?

I've attached a picture of the disc itself. The numbers on it are as follows:
86271-53022
464210-0971
DATA ver.07.1
and the "secret code" in the upper right is "U22" with a "D" under it.

At first glance from the long numbers it appears to be a 7.1 DVD for a Gen 5 system. But, the Gen 5 7.1 DVD that I have has a "U32" instead of a "U22" in the upper right. And, the actual contents of this disc are very different indeed.

When I stick this disc into a computer, the disc label is 464210-0960 instead of the 464210-0971 listed on the disc itself. That appears to be a number associated with the Gen 4 7.1 DVD (as does the number "U22").

The actual directory listing of the mystery disc is as follows:

Code:

D:\>dir
 Volume in drive D is 464210-0960
 Volume Serial Number is C7FC-60CA
 Directory of D:\
07/02/2007  01:08 PM        52,234,240 LOADING.KWI
05/31/2007  04:47 AM           308,904 05.CMP
06/15/2007  03:20 AM     3,118,733,344 ALLDATA.KWI
02/12/2003  01:35 AM           299,536 DICVCE56.KWI
06/02/2003  12:23 AM               117 METADATA.KWI
06/02/2003  12:23 AM                34 SPEC.KWI
04/08/2007  01:21 AM                17 VERSION.TXT
04/17/2002  09:40 AM               218 COVERAGE.TXT
07/04/2007  02:12 PM    <DIR>          COVERAGE
05/24/2007  06:16 PM             4,228 INDEXDAT.KWI
07/04/2007  02:12 PM    <DIR>          IDX
05/18/2001  01:58 AM           458,752 VIRTUAL0.DAT
05/18/2001  01:58 AM           458,752 VIRTUAL1.DAT
              11 File(s)  3,172,498,142 bytes
               2 Dir(s)               0 bytes free

Does that look familiar to anyone with a 7.1 disc for Gen 4 systems? For comparison's sake, here's the directory listing for a Gen 5 7.1 disc:

Code:

D:\>dir
 Volume in drive D is 464210-0971
 Volume Serial Number is DCFE-AEA1
 Directory of D:\
06/09/2007  12:26 AM               592 00.VNS
06/14/2007  02:31 PM    <DIR>          314
06/14/2007  02:31 PM    <DIR>          398
06/13/2007  03:35 AM       121,477,120 LOADING.KWI
06/14/2007  01:22 AM           904,440 05.CMP
06/13/2007  11:32 PM     2,533,926,912 ALLDATA.KWI
06/14/2007  02:31 PM    <DIR>          IDX
05/22/2001  10:30 PM           458,752 VIRTUAL0.DAT
05/22/2001  10:30 PM           458,752 VIRTUAL1.DAT
06/14/2007  12:08 AM     1,713,801,152 DICVCE56.KWI
06/14/2007  12:09 AM               117 METADATA.KWI
06/14/2007  12:11 AM                34 SPEC.KWI
06/14/2007  12:11 AM                17 VERSION.TXT
06/13/2007  11:32 PM               218 COVERAGE.TXT
06/13/2007  11:32 PM             1,730 COVERAGE.BIN
06/14/2007  02:31 PM    <DIR>          COVERAGE
06/14/2007  12:11 AM               174 PCT2MNG.KWI
06/14/2007  12:11 AM           591,872 PCT2DAT.KWI
06/14/2007  12:11 AM        59,906,048 PCT256D.KWI
06/14/2007  12:09 AM            59,392 KPCT256.KWI
06/14/2007  12:11 AM           219,136 VAR256D.KWI
06/14/2007  12:09 AM             4,700 KPCT2DT.KWI
06/14/2007  12:09 AM        22,358,016 GRA256D.KWI
06/14/2007  12:09 AM            59,392 KGRA256.KWI
06/14/2007  12:09 AM             2,048 INDEXDAT.KWI
06/14/2007  02:31 PM    <DIR>          ASYNTH
              21 File(s)  4,454,230,614 bytes
               5 Dir(s)               0 bytes free

A couple of other items of note: I inserted this disc into my 2006 (Gen 5) Prius nav system. This nav system had NOT previously seen a 7.1 disc. The nav system did NOT update the firmware when using this disc. It did appear to work, however. It showed maps on the display, and gave me voice directions. Some things seemed slow to respond, though, and I only tested for 5 minutes, so I didn't test voice recognition. Later, when I inserted a known good Gen 5 7.1 disc, my Prius DID update to the 7.1 "I Agree-Free" firmware.

Also, on the mystery disc, the .bmp files are readable in Windows. On all the known Gen 5 discs I have, the .bmp files are in some format that none of my graphics programs understand. On this mystery disc, I just double click them and they open right up. I've attached one here (converted to .jpg). Other than the yellow background (which I assume is identifying for transparency), does this look familiar to anyone with a Gen 4 system?

At this point, I can think of only a couple of theories as to what this is:

Theory 1: This is a perfectly normal Gen 4 7.1 disc that was mislabeled at the pressing plant somehow. This seems most likely, but then why does it work on my Gen 5 nav? For this theory to be true, the map formats would have to be the same across generations, and only have firmware or VR differences. I think that's the case, but I don't know for sure.

Theory 2: This is some crazy bootleg or hybrid of releases and someone went to great effort to make it look like a legit release, but mislabeled it. Seems doubtful, because this is a stamped disc, not a burn, and even has little things like hub labels on the other side that say "North America u22 L1" and "North America u22 L0"

So, any guesses? Who's up to the challenge of figuring out exactly what this thing is?

 

Anyone? Bueller?