Player fails to read some DVDs/Best writeable DVDs?

This is a strange problem for which I have a couple of possible solutions but I'd like some feedback, please.

At work, I have a Windows XP Pro computer, as do some of my colleagues. Others have Linux. The DVD player on my machine has the following serial number: HL-DT-ST RW/DVD GCC-4481B. This is per the device manager.

I cannot burn DVDs with it, despite its name, but that's okay, there is a portable DVD burner and I use it just fine. I am burning documentary data for archiving purposes, so that we can free up some server space.

This is not the first time I've had the problem I am about to describe. Yesterday, I burned 5 DVDs at the maximum write speed, SmartBurn 48x Max (note that sometimes it appears that the maximum write speed for the burner is 8.0x (10800KB/sec) and sometimes it is 6.0x (8100KB/sec), but I am quite sure that yesterday I was using 48x every time). The first 4 went off without a hitch and were playable in my machine. The 5th could not be played in my machine although the burner could see the DVD and its contents with no trouble. I tried it on a few of the other machines in the office. It did not work on a total of 3 XP Pro machines. I did work on a Linux machine and 1 XP Pro machine. So, wacky. Then I burned a second DVD, same data, same settings. And I got the same results.

Today, I burned a third copy of the same data. This time I slowed down the write speed to 32x max. And this time I was able to read the DVD in my own machine. A friend is now checking to see if she can read it on her machine (which is one of the other XP Pro machines that could not read the 2 DVDs from yesterday).

Oh, and this friend has had the exact same problem with burning DVDs. Some can be seen, some can't. Her machine is only 2 months old. Mine is 11 months old. These are, for all intents and purposes, new computers (certainly hers is). So the drives should not be failing quite so soon.

I did some online research and found this discussion: http://www.winguides.com/forums/showflat.php?Cat=&Board=genhardware&Number=121520&page=0&view=collapsed&sb=5&part= The thing of it is, the same problem was discussed in late '04 -- and that site still has not found a solution to the problem! Hence this is a known problem, at least known to some people.

Also, I checked for firmware upgrades and device driver upgrades. No dice. The reader is supposedly completely up to date.

The DVDs I have been using are all brand new, the stack was purchased maybe 2 months ago. It is called Fujifilm 100 pack DVD+R 4.7 GB/Go 120 Min, Disc for data and Video, up to 8x write speed. Now, I realize that I have been burning at a faster rate than the max, but 48x worked just fine for 4 DVDs, and then 32x worked just fine for the remaining DVD. So all of these speeds are way above 8x.

Therefore (sorry for the long story up there), I have 3 questions:

[color=blue][b](1) Is there any way to keep this problem from happening? (2) Did reducing the write speed actually fix the problem, or was it just a coincidence that perhaps I had picked a better DVD out of the stack? and (3) Is there a "best" brand of DVD that maybe doesn't do this, or at least doesn't do this quite so often? I estimate that out of a pack of 100 DVDs, my friend and I have probably pitched a total of 8 or so of them because of this problem. This is a lousy failure rate, so if a packet of a different type of DVD costs a little more, it's worth it to my company if we can avoid tossing so many DVDs.

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Thank you all, in advance.