I've use this app for a while and have had no issues changing my SMS alert. After the update, I cannot figure out how to change it. I have ffmpeg downloaded. Anyone else having issues or a fix??
It might not be compatible with 4.1. However, biteSMS allows for custom SMS ringtones. If you don't have biteSMS, you can also do it manually, which will take a bit more effort:
First, find the text ringtone you want (it should be in .caf format). SSH into your iPhone. Go to var > stash > Themes and then create a new folder (name it whatever). Within that new theme folder, create another folder called UISounds. Then move your ringtone to this folder. Rename the ringtone "sms-received1.caf". Apply the theme in Winterboard and respring. It should work then.