This is not a problem of CUPS. The implementation of custom paper sizes in CUPS works. The problem are the graphical user interfaces which do not (correctly) implement support for entering and using custom paper sizes.
system-config-printer is missing support for custom paper sizes completely.
The implementation in evince seems to be broken.
These are two independent bugs. Please post a new bug report for the evince problem.
This is not a problem of CUPS. The implementation of custom paper sizes in CUPS works. The problem are the graphical user interfaces which do not (correctly) implement support for entering and using custom paper sizes.
system- config- printer is missing support for custom paper sizes completely.
The implementation in evince seems to be broken.
These are two independent bugs. Please post a new bug report for the evince problem.