When backing up a game it is usually not needed to put a dummy file in, i think thats only needed when the ps2 cd you make is under 50mb. If your laser on your ps2 is acting up then i would, as it pushes the data to the outer edges, making it a little easier for it to read. If your games dont work then add a dummy in and see what happens, but like i said you probably wont need to.
Are you using CDVDGen 2.0 to rebuild the ISO? There is a dummy file maker program floating around. I think you can also use one for Dreamcast games. I have burned X-Men Legends II 1:1 and it plays fine so you shouldn't need the dummy anyways.
okay hopefully we can clear this up. You have 1 of 2 things:
1. I am assuming you have a dvdrip. A dvdrip is a game that is burnt on a "cd-r" disk that was originally on a DVD. The size is 700 mb and that won't work on swap magic.
2. If you have a burnt copy on DVD, then all is well. Go play!
If your answer is 1, then you have to extract all files to your PC HD......then patch files to DVD format. Use DVDscan 3.0 (I think) to patch to DVD. Then use cdps2gen and include a dummy file. The dummy file can be around 800 mb. I think you place it at the top, not sure. There is a dummy file maker (google it). If not you can open up notepad and type "xxxxxx" until you get 800 mb. I recommend doing the first option. The name of the file should be "DUMMY.DAT"
There you go, just burn the new iso to DVD-r at 2x.
I tried the dummy thing but didnt work, and it was to a dvd not cd-r.
I'll try to use another original dvd game in the next weeks and tell you the results, maybe the one i got is scratched..but is strange, i can play the original well (i havent finish the game so..im not sure if it will playable 100%).