LG VX-8600 / AX-8600

When attempting to send files to my 8600 from my laptop I receive an error message stating, "There is no space available on the device or computer you are transferring to. Free some space on the device or computer, and then try again." I verified that I have 10.6MB available space on my phone. What's the deal? I didn't think it was necessary to buy an SD card since the phone can hold a few songs itself. I tried sending both an Mp3 (3.5MB) and a 15k picture (just to make sure it wasn't the size of the song throwing the error message).

Thoughts?