I've got an unid as of a couple nights ago, and as the subject says, it's driving me bats! I snagged it at 4-something in the morning local time, and trying to match it to any webstream out there got me a whole lot of nowhere. Granted I was trying to do so by programming after the fact, as I'd taken the radio away from the local RFI for purposes of DXing and then come home, but nothing I found even came close to sounding right. I know this wasn't a harmonic, as I distinctly heard 'cuarenta' as part of the station's ID; I couldn't get the rest of it, grrrrr! Here's my log. Anybody have a clue?
540, UNID, 0906-0923. Tuned in to Britney Spears's Womanizer. More music followed, including Rihana's Where Have You Been, a Spanish-language rock song I didn't know, and the song about 'some nights I stay up cashing in my bad luck, some nights I call it a draw.' Who sings that? Owl City? Multiple difficult to copy ID's, at least one spoken and two musical, including frequency information which was audible. Into Spanish-language talk near tune-out, including definite references to people on facebook and text messages. Signal fair, mixing with other unknown 540's. SIO 333.
Yes, I know my knowledge of current pop songs is a bit lacking.

I initially thought this might have been La Nortenita out of Mexico, but the webstream sounded all wrong. Anyone know who the heck this could've been?