it first started as odd occurances and has now gotten to the point of anything attempted to be downloaded and saved freezes the game.
im using the new gui beta (before that 1.59B1)
i wonder if its due to the number of saved files within the 32mb save?
EDIT: just browsed the cycloDS forums and a quick fix seems to be running the game at 50% speed fixes the wifi downloading problem.
EDIT2: slow me didn't fix them problem for me at least.
im 99% certain at least for my sav etc is this: the game won't let you download any more games after a certain number has been reached. ive tested this multiple times by deleting 1/2/3/4 games then going to download new games and it has worked everytime up to the limit. (if i delete 1 game i can only download 1 game etc).
i don't know if this is to do with my sd card (4gb class 4) the cyclo firmware or AP.
It's probably the reformatting that fixed the problem, not the slow-mo. I had a sporadic problem with freezing as well but after reformatting it hasn't happened since, and no using slow-mo at all.
Think of it this way; since the save file for DIY is quite large, if the save file is fragmented it's going to be difficult for the game to save the file (especially since the game was designed to write data to a dedicated memory unit in a DS cart, not a MicroSD, so it wasn't designed to handle fragmented files). Reformatting and copying back the files essentially defrag the save file so the game saving should be a lot more stable.
Using slow-mo would help a bit since that would slow down the game-saving process and make it handle a fragmented save file better.