[SLE] Can I run a RedHat 7.3 binary on SUSE 9.3 ?

I've heard that linux binaries are not portable, but I'm not sure what
exactly is meant by this. If I have a statically linked binary, would it
have a good chance of running on another linux distro? My app is an old
RedHat 7.3 gui that uses wxWidgets, and I might need to port it to SUSE 9.x..
I was curius if it should run "as is", maybe by just supplying any other
Redhat binaries it expects to find.

When I google "portable linux binaries", the stuff I find makes it sound
like this wont work. Yet, I believe nVidia (and perhaps others) release a
"universal binary for linux". So maybe it does work?

Any suggestions?

thanks!