AAC streaming not working with latest version of Shoutcast (2.6)

I upgraded my Shoutcast server from 2.5 to 2.6, and now MBRecaster won't stream any AAC streams any more.
In the log file I get "source disconnected. Unable to sync to the stream. Please check the source is valid and in a supported format.". Even though it mentions "supported format", Shoutcast does support AAC streams.
When first installing my SC server I also had problems streaming AAC, but this was fixed by installing Quicktime. The only change now is the SC version.

How can I get AAC streaming working again?

I only tried AAC (tried 128 and 256), and those didn't work. I didn't try AAC+ as the bitrate is a bit too low for my taste.

I go to www.shoutcast.com/ then I log on in the upper right corner. When logged on I click my name at the top right, then choose "Manage your plan". From there I can "Download Shoutcast Server Software (2.6.0)".

I only have one available stream on my server, and I usually listen to it actively, so if I'm going to give you access we should set up some sort of private live chat so that I can make changes on the fly without having to go a day without music.

I created a support request with Shoutcast and their reply was that 2.6 is still in beta. Hopefully they'll fix this AAC issue in the final release.
After switching to 2.6 (and switching to MP3 streaming) my stream is much more stable than I reported here . Seeing as I changed two things I can't really tell if the micro stuttering comes from the server upgrade or the switch to MP3. Due to this stability increase I'll stick with the beta for now.

I looked into Icecast, but they don't officially support AAC. I've read that people have succeeded with AAC and Icecast, but the details are a bit lacking.
Have you been able to stream AAC to Icecast? If yes, is it a default installation of Icecast2, or do I need to do something special?