HELP!

I have only had my computer a couple of months and previously had no problem burning cds however as of late...it ejects halfway through and the info I get is that there may be something on the disc but of course there isnt.  Im using sonic recordnow also have tried realplayer, windows mediaplayerand using xp with the drag and drop to the drive and then it will say cannot copy file regardless if it is pictures, data, or music.  I uninstalled/reninstalled sonic to no avail.  When I did uninstall sonic, there were two other related programs in the add/remove that I assumed went with sonic so I uninstalled those as well and when I did the reinstall they were not there afterwards.  I have tried almost everything I can think of and have gone through almost a full spindle of cds and am at my wits end.  System restore is not an option as I have tons of data downloaded since the problems first occurred and dont want to lose it (I have no floppy drive either--didnt think I needed it at the time---DUH ERICA!!)  I have not added any software or hardware of any kind.  Device manager says all is ok.  drivers all current.  The drive is HL-DL-ST RW/DVD GCC 4481b, Im running XP, P4-2.66-80g HD-256mem.  SOMEbody help if possible!!!

Erica