I made that csv file with the first row, and I tried to imprort it, and was successfull.
Then I splited the 713 rows to 100rows/file, and all of them worked :O
The whole file was only 100kbyte with the 713 rows, so no size limit could be failed.
I don't know what was the problem, but I could solved it.
You should make a useable import / export function, I think all users would be happy with it, and it is really not an extra thing :/