Can't read or write CDs

I have an Inspiron 1525 laptop 32 bit with Windows Vista Home Premium.

When I first bought the computer, I had no problem burning and reading CDs.

Lately I have been having problems reading and writing CDs.

When I started having problems, I would have to try several times to burn a CD before it was successful.  Now when I try to burn a CD, it instructs me to insert a blank CD when I already have a CD in the burner.  When I go to "my computer" and look at Drive E, it doesn't show any data on the CD when there is data.  Also, it tells me to format the CD and the formatting is never successful.

The CDs that I burned before I started having problems still work fine, it is just the CDs that I burned after I started having problems that are no longer working.

I tried "Microsoft Fix It" on this site and it told me to insert a readable CD in the drive when there already was a readable CD in the drive.

Why are my old CDs still working fine, but the new ones no longer work at all?