I recently upgraded controllers (620) from 5.0.3.3 to 6.1.3.6. I have one location that called in to report that wireless coverage in the office was severely degraded, and that previously they've had no issues for 2+ years.
I ran through all the usual - update drivers, patches, etc.
I put the office in Airwave and the office clearly did not have enough coverage - 2 APs & approximately 10k sq ft. That gives me enough "evidence" that I need to give them a few more APs to cover the dead areas, but unfortunately it takes time to get approval, ship, and coordinate with a vendor to do the install.
Still, it was bothering me that nothing had changed other than the firmware upgrade. I've upgraded 75% of our offices and had no other complaints.
Looking at the new functionality on the controller, I just couldn't find any information to support what was being reported. Everything was being reported within "acceptable" ranges. I apparently lost historical data in Airwave during the last upgrade, so I could only go back a few weeks - not enough in there to call the user crazy.
After dealing with it for a week, I decided to roll back to the older firmware. Called the user today and got "did you do something? Everything is better!"
Any reason an upgrade to the latest would cause something like this?