This has happened with me on several occations, but here's the kicker, it wasn't my amp or cables, it was my old apartment!
I played my Dual Rec, Rectoverb, Tube Works Tube Driver, and even my buddy's Marshall, all with the same problem. At least it was KBPI coming through the amp (the local rock station)! But when I played at my band's practice room with the same amps, it didn't happen at all.
I used to think it was my cables, but I changed them out with Monster cables and even experimented without running the fx loop. Just a 15ft Monster cable going into the input of my amp from my guitar, and a 3 ft. Monster speaker cable going from my amp to my speaker cab.
I tried different guitars, cables, amps, cabs, etc., but there was only one constant........my apartment!
I think it was the wiring in my apartment that was picking up the local radio station. Good AC power is hard to find anywhere, especially my old apartment.
...I don't know if this helps your situation, but it might be "where" you are playing, not "what" you are playing. Try the same set up in a different room or better yet, in a different house/practice space and see if that dosn't help your problem. If all of your other gear is up to snuff (guitar, cables, amps, cabs, etc.) it could be just as simple as changing where you play.
On a side note..........I don't know if this will help you feel any better, but if you listen to the begining of "Flying in a Blue Dream" by Joe Satriani and hear the boy talking in the background during the intro, well, that was caused by radio interferance when he was recording that album, and he decided to keep it in the song!
You might be in good shape when you go to record....or hopefully you can at least try to filter out the salsa station. :wink: