Catalyst 3.0 on a 3.5 inch disk is not compatible with the Apple 3.5 disk drive. Quark does not currently have a fix for this problem.
The only way to use Catalyst 3.0 on an Apple IIGS is by using the 5.25 inch version or by using only UniDisk 3.5's on the Apple IIGS.
A book mentions a Catalyst version 4.0 for the Apple IIGS. Such a version does not exist and is not being worked on.