If you do get them backwards, it won't blow anything up. It just ever so slightly compromises the fusing on the input. I don't have one of my 29PFX's available right now to check, but I can look the next time I'm near one if you still haven't figured it out by then.
FYI, if you're in Europe, be sure the degauss coil is hooked up to the 220-240V connection, not the 120V. I would suspect that if you have it hooked up to the 120V connection, you'll fry your degauss coil. Everything else on the monitor is free-range, and you don't have to worry about input voltage.