The * Limit Groups list under user profile Notification settings should be in alphabetical order, and not in what appear to be the order the groups were created. I guess it is currently sorted by Group ID?
It’s hard to find the ones you want when you have a lot of groups.
You’re right, it’s currently sorting by ID.
However, I personally see this as a bug.
Feel free to create a bug report if you’d like. Please also mention this thread.
If you’re a paying hosted customer, you can also drop us a mail, this will priotize your bug report.