***When deployed using PoE, the power drawn from the power sourcing equipment will be higher by some amount dependent on the length of the interconnecting cable. This additional power may be as high as 2.45W, bringing the total system power draw (access point + cabling) to 15.4W.
your Error message indicates: This message indicates the access point is operating at full power because it has notreceived any CDP packets within the timeout period. This condition indicates your access point isconnected to a non-Cisco power source.
I use SecureCRT and never had that issue. It also can be an issue with the setting you have set in your serial. If you telnet or ssh to the AP, does it work? I would try a different USB to serial cable and or console cable and machine. Try to determine if one of those is causing the issue.