burning Data DVDs - please help

I'm using Nero 6 to burn data dvds and so far none of them have been successful. The burn completes and Nero tells me it was sucessful, but when I attempt to read one of the burned DVDs, windows tells me to insert a disk into the drive. Attempting to explore/open one of the burned DVDs also apparently managed to crash Explorer. I've created a successful data DVD on this machine before, so I know the burner is capable of doing it. One time I chose to finalize the DVD and another time I chose not to. That change didn't affect the final dvd at all, and so far none of them have worked.

I'm using Sony DVD+R disks and I also tried my burned dvds in my other disk drive. both are DVD readers and one is the writer. Please help me figure out what to do; should I try another software? I know what I'm doing, or at least, I thought I did. It's always worked in the past.

edits/notes:
do I need to format the blank dvd before I try to burn to it?

I'm not chosing to make a bootable disk either, so I can't understand why windows or my dvd-rom drives can't read the files on it.

Trying to burn a Nero Image Rom was downright unsuccessful.

I tweaked settings and also reverted to defaults for each individual burn attempt. I also tried using my copy of Nero Express. I even re-installed my copy of Nero 7 Premium to see if it would work. Now I'm using Nero 7 instead of 6 but I still have my old copy of it.

1st attempt was 4+ gigs of audio files
2nd attempt was 4+ gigs of video files
3rd attempt was 3+ gigs of both
4th attempt was 3+ gigs of disk images (legal backups, thank you very much)
5th latest attempt which failed outright was a Nero Burn Rom

Now the process fails outright every time with the error:
Could not complete end of Disk-at-Once



please advise (!!!)

Make sure that in the drop down box for recorders your DVD Burner is showing and not "image recorder."

I have heard bad things about the first nero 7 release
7.0.0.0 has lots of bugs,this is from other forums ,not my experiance
I have 6.016 ,but don't burn much with it anymore
though I'm sure it still works

CD burner

I couldn't get on with Nero. I went for Cdburnerxp.

I got the freeware program IronDuke mentioned, CdburnerXP. It completed a 'successful' burn, but still, when I ask my drive to read the disk: nothing. it asks me to insert a disk. Now, after three different burning softwares completed what they deemed successful burns, I'm suspecting that it's a read error. How can I determine if that is the case, (besides testing it on another machine,) and what am I supposed to do about it?

when I try to find the name of my drives all I get is this:
HL-DT-ST DVDRAM GSA-4040B
JLMS XJ-HD1665

They came installed with my Gateway machine and they've never given me any trouble. I'm able to play storebought DVD movies and games just fine, so maybe it isn't a reading error. Either way, I'm stuck. Please help me if you can.

edit:
a benchmarking and info gathering program (Nero CD-DVD Speed, Nero InfoTool) seem to lock up when they attempt to access a drive which holds one of my burned DVDs. any program which attempts to refresh/access the drive that holds my DVD slows way down and either stops responding or never successfully accesses the drive.