I just got the car in the mail a few days ago and ran it for the first time yesterday. it was a rtr scte with the losi motor/esc, which I've read are rebranded castle creations stuff.
I haven't tried a different servo yet, no. I just tried the different receiver and it worked fine.
and I have no idea if it did it before. I'll try with the crappy stock servo to see if that's the problem.

edit: I put the receiver in my m05 with a futaba s3010, and it seems to be working okay now. The d226f was definitely drawing too much power.