[Coco] rainbow volume/# strangeness

[Aaron Wolfe]

I've almost got a complete collection of Rainbows, thanks to all
who've helped.  Once I have them OCRed and down to a more manageable
size (all are < 50MB, most half that), I'll put up a torrent, upload
to malted, etc.

As I'm naming the files for consistency, I've run into some weird
stuff with the volume #s.

Aug 88 is Volume VIII No 01, Sep 88 is Vol. VIII No 02,  Oct 88 is
Vol. VIII No 03.  Normal so far... but November 88 is Vol. "VIIII" No
04?  Then December 88 is Vol VII No
05, same as December 87 was.   Next, January 1989 is also Vol VII No
05.  So we have 3 issues with this designation?
Feb 89 is Vol VII No 6, March is Vol VII No 7.  But, April is Vol VIII
No 09 (which I think is "right").  Then May 89 goes back into Vol VII,
but maintain the sequence # 10.  After that things seem to be normal
so far.

Is this a known thing with an explanation?  I'm interested in what
happened there.
-Aaron