When you tried via the CSLive/BrowserLab panel inside Dw, did you see the messages indicating that the files were being transfered to BrowserLab (messages under the progress bar)?
Have you tried deleting your browser cache/cookie to see if that helps. please try that and please let us know if that fixes the issue or helps you move forward.
one other thing to try these steps in the following sequence
- make sure DW CS 5.5 is closed
- launch BrowserLab standalone in the browser & login
- then relaunch DW CS 5.5
please let us know if this works for you.