[horde] "Login failed because your username or password was entered incorrectly."

[Robert P. J. Day]

   i hope this is the right forum for this.  i just "dist-upgraded" a  
debian sarge (3.1) server to etch (4.0), and people who used to be  
able to use a horde client to connect to this system are suddenly  
getting the above diagnostic.

   i'm googling on that error message to i've got a fair bit to read,  
but if anyone has any strokes of genius as to why that upgrade would  
cause that problem, i would be ever so grateful.

rday