1. Get a QIF containing split transactions (I used Moneydance generated QIF file)
2. Import it into KMyMoney
3. Look up the split transaction in the appropriate account. If original transaction contained values 10, 20 and 30, you'll end up having two transactions in the list - original one of 60 (summ of all splits), and dup one of 30.
It'd be really good if you can get it fixed since it really stops me from moving to the program - I hav years of splits - can't really edit them all manually!