Problems sharing CD-RW between PC’s

I have a CD burner on my desktop. I use it primarily for burning CD-R files and it works fine.

Recently, however, I have experienced problems writing CD-RW disks that can be read on other PC’s. It seems the first time I write to a CD-RW, everything works as planned and I am able to read it on other PC’s. However, when I try to add additional files to the same CD, things start to fall apart. It appears from the desktop(source) that everything writes to the cd. I can go to My computer and see the files I wrote. When I take the disk to another PC, I am unable to see the new files, however, I can still see the old ones. In addition, if I look at the properties of the drive, it reports the disk is full even though it has only 40 mb written to it.

I have tried different software but still have the same problem. Please help!!