The strange com problems I was experiencing went away with new kernels built
after a "make clean" in the kernel compile directory.

I guess some of my .o files were newer than some supped files, and older
than others, causing my newest kernels to be hosed.

Hmm...I guess I've learned my lesson: to "make clean" in the kernel build
directory as the first step in troubleshooting weird kernel problems...

Thanks,
Glenn