When I try to burn dvds in Realplayer Plus SP, the error "Internal Software Error" pops up & burning fails.. I paid money I didn't even havr to spare for this so I'm very frustrating over losing my money..

This is a driver problem. I had it as well. Go to your PC manufacturer web site, support, downloads, put in your model number, your operating system and scroll down the drivers until you find your optical equipment. Trouble is, there may be more than one drivers. Download them all and install them; your computer will know which one is which.

dc5800
no OS stated
no burn software stated (use imgburn (free it is)

the drive must be clean, (optics)
the media needs to be good, dvd-r (top brands best) others not.
OS not infected, with virus is this XP the virus magnet?
the burn-software needs to be top quality, imgburn is that.
ive never ever burned a coaster with imgburn , 100's of time, more really. been burning since the First DVD-r was sold, for sure.
no the things that chager or corrupting of the OS
or dirty optics in the DRIVE.
even dust, simple dust.

Usually means the media is not compatible or is caused due to a bad disc...changing the disc will eliminate the problem...it may be due to a bad brand of disc as well. Look at your disks are they + R or - R, Some burners even though they say +/- they have problems with + R disks and others with - R. Nero 7 and Realplayer have nothing to do with your problem. Try changing your media brand, I have good results with Sony.

Also burning to a folder then disk helps with this problem.

First, stick with DVD's that have worked in the past; Verbatim is the best.

Perhaps the laser needs cleaning. If you have a can of compressed air, open the DVD tray and shoot a few seconds of air in the DVD drive, being careful not to tilt the can. Do not shake the canned air bedore using.
If there is still a problem, use a laser lens cleaner ($13 Radio Shack). It is an audio CD with a row of brushes on it. Turn on your speakers / headphones and follow the instructions. No chemicals involved.

1. check ur dvd can burn dvd or just read dvd 2. your burning software my not compatible with yor optical drive

Do you have a dual layer burner, you need one to burn dual layer dvds that may be your problem hope it helps

DVD discs come in two capacity sizes.
Single layer DVD have a capacity of 4.7 Gb
Dual layer DVD have a capacity of 8.5 Gb
Some DVD burners are single layer burners only and cannot burn dual layer discs.
The error message you are getting would indicate that the disc you are using is not large enough to copy all your program material.

My solution is going to require entering the unit, so you may want a qualified service tech to perform the job, but i would check the connection between the burner and the board. 

This happened to me also. I fixed the problem by buying new DVD discs, sometimes the mac's rom doesnt like particular discs. Its a trial and error thing with which ones it will use. Make sure you are using the latest version of Roxio toast to burn with, also make sure your ROM is DVD-R.

If all this fails, it could be your writer in the rom. Try burning a CD, if that works it will be the above problems.

Try using discs with a GOLD BOTTOM, it seemed to work for me.

you are probably missing the correct codecs for what you are trying to do. easiest solution is to donwload something like ace mega codec pack. http://www.free-codecs.com/download/ACE_Mega_CoDecS_Pack.htm install and try again