@Rik I am having a similar problem.  I have 5 EAPs (3 220's, 2 225).  In using the controller software, shortly after getting everything working, all EAPs go into a disconnected reported state, however they seem to be still functional. 

I have AVG Internet Security and if I shut off 'Enhanced Firewall', the status on the EAPs go back to connected mode.   I made the mistake of reseting a couple of the EAPs in an effort to get them running WITH the firewall, but all I did was make two of them no longer function, while still looking like all were not functioning on the controller software (i.e disconnected). I verified that if I turn the enhanced firewall back on, that the EAPs go back into a reported disconnect state on the controller software. 

Is there a simple way to resolve this?  Do I need to do something to the controller software or AVG or both?   Also, in getting the two EAPs back online being factory reset and all, they did not want to be activated until I entered the default factory admin name and pw, rather than the name and pw of the rest .. would obviously like to correct that as well. 

Thanks for any and all assistance on this. 

@Rik 
PS - I did read in one of these discussions here about adding ports to be open and I tried that, but obviously it didn't work or I didn't add them in the right place or something ...