Older clients fail with 1.3.4 server

[grant basham]

I am having a number of problems with older cups clients from redhat
enterprise linux v 3 that worked ok with a 1.2.11 cups server.

I am getting client-error-bad-request on CUPS-Get-Printers
and CUPS-Get-Classes.  This is from cups 1.1.17 clients talking to a 1.3.4 server.  The clients worked on a 1.2.11 server with cupsd.conf identical to the 1.3.4 server.

The servers are 1.2.11 (on FedoraCore 7) and 1.3.4 (on Redhat Enterprise v 5).  Both are vanilla builds with the same /etc/cups/*.conf and ppd files.

Any assistance is appreciated.