Popcorn 3 Does not play back DVDs after first eject

I am using Pinnacle Video Capture for Mac to record my old VHS video onto my computer. This puts it into mpeg4 format and saves into ITunes. From here I am editing with IMovies. Evereything works perfect. From here I Use Popcorn 3 to burn my final edited movie. I am burning onto Memorex DVD-R 16x 4.7GB 120min. No problem, once finished I close all my programs and open Mac DVD Player 5.0.3 at this point the DVD plays perfect. But when I eject the DVD and reinsert it into my Mac the computer is unable to read the disc. No errors or notices show. I hear the player trying to read a few times then it just ejects. What is going on. I am using a MacBook OSX 10.5.8, 2.4 GHZ Intel Core 2 Duo, 2 GB 667 MHz DDR@ SDRAM, HL-DT-ST DVDRW GSA-S10N:
Firmware Revision: BP10
Interconnect: ATAPI
Burn Support: Yes (Apple Shipping Drive)
Cache: 2048 KB
Reads DVD: Yes
CD-Write: -R, -RW
DVD-Write: -R, -R DL, -RW, +R, +R DL, +RW
Write Strategies: CD-TAO, CD-SAO, CD-Raw, DVD-DAO
Media: Insert media and refresh to show available burn speeds