I've had some dodgy experiences with save converting to ez4, but realistically it uses the same raw save format, the only difference being R4 padds out all its saves into 512kb (rather than the usual 256kb for ez excluding the odd game) thus the end 256kb needs to be cut off.
Hmm. Something weird. When I put a clean EBA rom into it to test it, I completed one stage and that was when I decided to put on my dave from my R4. I was having trouble getting it to recognise the save so I deleted the game AND the save data from my Mini SD and rewrote the same EBA rom. Loaded it up... and it STILL shows the save data where I completed the one stage. My only thought was that the save data must be stored on the actual EZF IV. So how do I get rid of it and make it recognise a lot of the saves from my R4?
the ez flash iv saves the last played rom on boot up, i have had this same problem, so lets say you hit save on a game and then turn it off, well its not really saved, to save you need to turn your ds back on and your ez flash iv will give a saving message, (the chinese thing is because its set to chinese by default, you have to change it to english), you then can turn it off and transfer the saves, unlike the R4 which saves right away, a ez flash iv you need to turn your ds off and then back on for it to save, its a hassle since you need to power your ds back on just to save.