Wow. You have try so many dvd author problems. That is enough info. I 'm not sure about your ( RIDATA DVD+RW/+R ) IDE drive. It should be OK where other's can be done. Don't worry, it can be write DVDs. Just need some update for the following step...
My OS is Windows 2000 Professional SP3. Soft installed on my PC, Sonic DVDit 2.54, DVDXcopy 1.30, Dazzle DVD Complete, DVD Cloner 1.90, Ulead DVD Workshop 1.20, Ulead Movie Factory 1.20, DVD Wise and PrimoDVD 2.0. All this NO problem at all. My burner is Pioneer DVD-R/RW A03 Firmware 1.54.
Windows Me may have bugs on the ASPI driver detect your ( RIDATA DVD+RW/+R ) That's why some author soft can't see your DVD+R/RW drive. Check your ASPI. I have a site...check it
http://www.adaptec.com/worldwide/support/driverdetail.html?cat=/Product/ASPI-4.70&filekey=aspi_v470.exe
If you decided to upgrade your OS, use Windows 2000 Professional SP3. Some DVD Authoring had to be support in NT based mode. Much more stable OS. They also support Windows XP Professional SP1.
For your Sonic DVDit, what is your version ? The New Version is 2.54. Update more DVD writer drive. Check your version. update the new patch file. For the rest, you need to update new patch or installed new version. It may help you to burn DVDs.
Firmware Flash update may need it.
http://forum.firmware-flash.com/portal.php