Cannot export properly; strange problem

I decided to make a cover with a friend and I ended up with 10 audio tracks as a finished product. 1 of the tracks (the song we backtracked too) is muted but all the others aren't muted. when i play back it sounds the way I want it to but when I export, I can only hear the 2 guitars! this is annoying as i wanted to get this uploaded immediately.

 when I recorded the drums I also noticed that i had a live-echo of the drums themselves when I was playing; livestreaming through the headphones. I didn't have  input echo checked when recording or playing after I noticed it, but it kept giving a live sound through the mics. Maybe this would be the case with the export? It probably muted the tracks even though mute wasn't selected, thus when exported you only hear 2 guitars..

can anyone solve this problem? thanks :/

I know you've sorted it now but the export function only exports selected tracks, or if none are selected all of them.

For future reference, just in case that was the reason.