I took my car in for service for this issue (The central locking switch in the cabin didn't work). When I demonstrated the switch to the service writer, it worked fine. I felt like an idiot. later on, I figure out the issue.
Last weekend I pulled fuse 35 (to disable the daytime running lights). When I disabled the daytime running lights, the switch worked. It's a wierd thing - when the lights are on, the switch doesn't work. Light's off - switch works fine. It doesn't seem like a short, must be some kind of programming error.
The problem ended up being an assembly issue. The wiring harness for the central locks tuck toward the rear next to the e-brake. The harness in my car was pinched by the e-brake, shorting the circuit. Somehow when the fuse 35 was pulled, some witchcraft having something to do with a common ground w/ the central lock circuit enabled the switch - when the fuse was pulled
Anyway - the fine tech's at the dealership fixed the problem.
On another note - was give a Caddy CTS (3.6) as a loaner. It's a pretty damn nice car - has the SAAB vent controls, looks like the same AC software. tight back seat, but a marginally nicer interior.