Under powered PC?

Hi fellow simmers!I have a strange issue sine approx. a month.PC has GoFlight Airliner Configuration, TrackIR, TrackClip Pro, Saitek's Yoke, X52pro, Rudder Peddals, Th2Go and keyboard/mouse connected via USB ports.Every time I disconnect PC from power source and boot the OS I have to unplug and plug again Yoke and GF-166 panel. I tried to switch it to different port but without success. According to Everest, +5V has 5,24V output (no matter how many devices are plugged), my PSU is Corsair 850W, according to online PSU calculator, I need at least 730W (20 USB devices used for calculations).Sometimes, when I unplug/plug my devices in order to get them to work, my Th2Go receives not enough current (that's my guess)and the display driver stops working with BSOD. Please note it is rock solid when not dealing with plug/unplug.What the heck? MoBo? It is Gigabyte P45 with 8x USB backpanel + 2x USB at front (not used at all), I also use PCI-E extension card with 4x USB. PSU is dead? Something else?Please help, I'm grounded...It worked in exactly the same configuration for a Year or so without a problem.