Hi, I had this problem in v6 and still have it in 126.96.36.199....
Anti-Malware does not register itself with the Action Centre until the second true update of signatures. I'll try and explain:
When my machine boots up Anti-Malware updates signatures as soon as it starts.
The Action Centre checks for problems about a minute after Windows boots (after the initial signature update)
It reports that Anti-Malware is turned off (not that it is out of date) both for anti-virus and spyware (2 problems detected). If I click on "Turn On" from the Action Centre the Anti-Malware GUI is opened but the problem remains.
This does not correct itself until the first 'update' of signatures is done after this point (ie if there are no updated signatures to download then it remains an issues, as soon as updated signatures are downloaded and installed the Action Centre is happy).
This is a problem for me as I use Microsoft UAG for remote access to systems. One of the things it does before allowing access is to determine that you are using AV and Firewall (it gets this info from Action Centre). So I can't use this until the next lot of signatures are released after I start my PC.
If you require any further info please let me know - it would be great to fix this in the beta.