Newsgroup with large article numbers

[Bob Babcock]

Gnus doesn't seem to like article numbers greater than hex 7ffffff 
(134,217,727 decimal).  This is 4 bits sooner than I would expect it to 
break, but I see references to emacs using 28-bit integers so it must be 
using the last few bits for something else.  I wouldn't normally use gnus 
for newsgroups with this many messages, but when I did try it, gnus thought 
there were no new messages.  Is there a workaround?

I see this behavior with:
gnus 5.9.0, emacs 21.3.1, Win/2K
gnus 5.8.8, emacs 20.7.1, RedHat Linux 7.1 (x86)