That's standard. Only 5 region changes to a drive and no changing that. You can get around it by using region free software instead. If you want payware you can use AnyDVD or if you want freeware there's DVD43 with the Patin Coufin driver. Look in the Afterdawn software section.
Yes this is a common problem with dvd drives. This is why most owners install a HACKED firmware somewhere along the way. Hacked firmware usually makes the drive region free plus faster rip speeds and better media compatibility. Best to wait until your warranty is up since this will void it.
I don't know about any standalone converters, but there are DVD players that will do the conversion for you. If you go back to the first page of the thread you'll see that someone said his Pioneer DV563 converted from PAL to NTSC, and that's probably about the best value in DVD players out there right now. It plays pretty much anything you throw at it (including DVD-A and SACD), it's Progressive scan, and you can get it for around $150 here in the States. In fact since my old Sanyo is dying I'm planning on getting that player myself sometime in the near future.
If you're looking for something cheaper, I know I've heard of Chinese players that will do the conversion, but I'm not sure which ones.
Rip the DVD first to disk with DVD Decrypter, then use DVD Shrink to remove the region code.
I found that this worked with my DVD player. However, my PC DVD drive still seemed to complain about the region when I tried to play it with Sonic CinePlayer.
Note that you will still have the NTSC/PAl problem. On my TV I have a scrolling image, but the sound is OK.
Now going to try Vegas to do the Pal>NTSC conversion.