(continued...)
I told Finder to open iDVD (which was already opened & running) and iDVD reset the burning process for the new disc.
After the benign failure of the Verbatim & generic DVD-R's, I tried the HP's. About an hour (?) into the multiplexing/burning step, the disc ejected, although iDVD didn't blink (no prompt for a new disc, no spinning beach ball of death); iDVD continued as if it was still burning. After playing tennis with the disc, reinserting it & having it spit out various times, I finally took the DVD out. When the DVD drawer was in, with no media, iDVD happily continued with no error message. I tried to cancel the burn (using the on screen/built in prompt) with no luck. I then resorted to finder, to see if iDVD was "not responding" but Finder didn't think there was a problem (unlike with the NEC, when I always got a "program not responding" message). I ended up Force Quitting iDVD after some more time (to see if it would sort itself out; it didn't). The HP disc had been partially written. So, here was my first coaster after the Pioneer reinstall. The HP's are rated as 8x, like the verbatims. I had never tried an HP disc before I had the NEC drive, so I have no precedent (like the no-go Verbatim 8-x's) to know whether or not the partial burn was an anomaly or something new.
After the HP DVD-R failure, I tried another Imation CD-R, using iTunes to burn music, and it worked no problem.
I can try another HP or generic DVD-R, or another program to try and burn something, but at this point, I figured I had better post & see what everyone thought. For the record, after reinstall, the Pioneer will not work with DVD-R's, but will work with CD-R's (based on a very limited sample).
Again, sorry this is so long, and I would be happy to post a summary of everything I have tried, if it will help. Now that the Pioneer is back in the G4, I'm not sure how to troubleshoot the NEC. The NEC was never out of its original packaging between purchase and installation, so no chance that dust got on it somewhere. I'm inclined to think that I just got a bad NEC drive, but now that the original Pioneer no longer likes burning DVD's, I have to wonder. On the plus side, with the Pioneer, the Finder issues seem to have gone away, but it has only been running since this morning. If something odd happens, with the Pioneer & Finder, I will post it.
Although I am happy I can again (apparently) burn CD's, I really need to burn video DVD's for work related projects; it's why I upgraded the superdrive in the first place. At this point, I have already missed two deadlines and even with the Pioneer, I can't burn DVD's at all. I can do another clean install of Tiger if anyone thinks it will help.
My next move is to head to the computer store tomorrow to get a new ATA cable... any other suggestions?
PS -- the most chronic problem I had with the NEC drive & Finder is that almost every time I needed to eject a disc after a program crash, I had to do a
cold reboot to be able to get the disc out.
A close number two is that once the drive caused (?) a crash in a program, finder would also crash in short order, forcing a reboot to be able to do anything (relaunching finder didn't work in these instances).
Both of these problems were frequently simultaneous.