Near Death Experience in Chattanooga

So I decided to fly around some more with the new Saitek flight controls. I did another pattern flight around Dalton earlier but then decided to fly up to Chattanooga and back. The flight up was uneventful and landing was pretty good. The main problem now is my chair rolling around while I try to push the rudder pedals. I definitely need to figure out some other kind of chair for flying.

Anyway, on take-off from Chattanooga I went to full power, accelerated and started to climb. Less than 500 feet up, I was climbing and with an increasing climb rate, so I felt like it was safe to retract the flaps.

As the flaps came back to fully retracted though, the plane rolled suddenly to the left. I jerked the yoke back to the right which had some effect but then the plane rolled even more dramatically to the left, all the way on it's side and started diving towards the airport (since wings don't lift too well when they are perpendicular to the ground).

In this cockpit view you can see I'm sideways, and if you zoom in you can see my altimeter is reading 1,000 feet, which is less than 300 feet up in the air since the runway is at 7-something.

Unbelievably, I managed to level off and pull up, probably about a hundred feet off the deck and start to climb again. Once I got her leveled, she didn't misbehave any more and the flight back to Dalton went fine. Probably one of my best landings in fact:

Not sure what to make of that. Was it an FSX glitch? An issue with the add-on (non-Microsoft) plane I was flying? An erroneous control input from the new flight yoke? Or do some planes suddenly go into a roll like that when flaps are retracted?

I replayed it several times and couldn't figure out anything I had done differently from prior takeoffs. I also Googled looking for answers but couldn't find anything.

Best guess is an issue with the Saitek yoke, since that's the only thing that's changed with my setup as of today, but I'm still not sure about it. I'll add an update if I figure this out, but for now I think I'm done flying for the evening.

(UPDATE: Still working on this, but in FSX I was checking the settings and saw that the toe brakes on the rudder pedals were set to control the X and Y axis, same as the yoke. Perhaps during the climb I pressed the left toe brake in error, sending me into a roll. I've reconfigured those to the brake function, so we'll keep flying and see if this happens again)