I have been receiving the error= -4 code on my YSMenu'd R4III Upgrade. (I think it's modeled off of DSTT not sure)
I downloaded and followed this:
http://gbatemp.net/t237398-waio-woodallinone? (put the contents of the build folder in the root)
When I load up the R4 I go into WAIO.nds and then from there load up WoodR4dldi.nds.
Then I load up a Rom that was patched by the Universal Patch by Rudolf and the EXP patch (both found on this thread one on main page one on some other page of this tread)
It works completely without saving problems or anything. R4 Clones and DSTT might want to try this. I'm not sure if it will work or not though...