No, that's the only place I upload my songs. Did you get a warning for the entire site, or just my song?
I use Bitdefender and have never had any warnings about that site, and have never gotten any viruses
from them. I think it's safe, especially if you're just listening and not downloading anything.
My guess is that you were getting a false positive from their inline player. That's the only thing I can think of.
EDIT: I just did some checking on SoundClick in their help section. The only thing I could find concerning trouble with security software was an article on how Zone Alarm automatically blocks any Flash audio streams for security reasons and the user needs to add an exception to allow the audio player to work. I'm wondering if your software might be experiencing the same issue?