Windows 7 And Rewritable Cds -- Problem!, NEED HELP IMMEDIATELY!

[aussiemcgr]

Ok, I'm having to make some last minute changes on a project I'm submitting in a contest this Saturday and I'm getting an unexpected issue.

My project is a java program, but that isnt the problem. The problem I'm getting is that when I tried compiling I got an error telling me I couldnt save onto the disk. When I checked the disk, it seems to think I have used up the entire 574mb when I have actually only used about 6mb.

To answer the questions before they are asked:
1) Yes, it is a Read and Write cd, I have made changes on it previously without this problem.
2) Yes, I understand the concept of "free space" however that does not apply here because I never actually formatted the disk to a fixed size and instead formatted it to be a storage device instead of a burning device. PLUS, it says "0 bytes free of 574mb" instead of the "0 bytes free of 6mb" it would say if it was formatted to be burned.
3) Yes I have successfully made changes to this program on this computer using this disk.
4) Yes the project has to be on a CD, not a USB or anything like that.

Can anyone help me out here? I initially thought it was a stupid privileges problem but after looking at the free space on the disk I no longer think that. I will be very grateful for helpful answers.

EDIT
It would seem the disk has been automatically set to read-only. WTF would have caused this?