>600MB being read as 6MB?

OK, I burned a bunch of files from My DOcuments to a CDRW disk a while ago, I used muli-session writting (does that mean I can still over write stuff I've written to the disk before?). Just a few minutes ago, the disk was being read just fine, now all I'm seeing is a folder that I never even put on the disk (pretty sure)...and it reads the disk as being ~6MB big...I had over 600MB worth of stuff on this disk... :

Anyone know what is wrong here? Is there a way to reformat this CDRW disk?

In Nero Burning Rom, click the Recorder option, then select Erase Rewritable disk. Not sure in Roxio, but if thats what you use, do a search of Help.