Wierd error w/make-kpkg

[Steve Gore <srgore@ev1.net>]

I just got the newest potato debs (which included a new kernel-package, v 
6.13).

Astra:/usr/src/linux# make-kpkg --revision=custom.1.2 kernel_image
 Error: The revision string may only contain
 alphanumerics and  the  characters  +  .
 The current value is: custom.1.2
 Aborting.

I've compiled at least a dozen kernel variations using "make-kpkg", and I 
might be losing my mind, but I swear this is the syntax I've been using all 
along.
Also, this is the syntax suggested in the docs, the man page, and even in the 
stupid error message!

Dazed and Confused,
Steve