I haven't had any issues.
You know the problem with shared RF spectrum is sometimes someone else does something that causes you a problem - even though you changed nothing.
It could be new cordless phones, RF microphones, cordless headsets, just about anything that uses RF. Has anyone introduced new "anything" into the environment?
Don't rule out that the problem could be nothing to do with something you have changed.
It could even be someone malicious.
A channel width of 80Mhz is a tad hopefull. I often like going for 40Mhz if the environment is not dense.
Does Wireless Sentry report any security issues?
Does the spectrum analyzer show all channels are good, or is part of the RF spectrum being chewed up by something?
And I hate to say it - but have you tried giving the APs a reboot?