I have had similiar problems where certain apps work and others perform poorly, especially on wireless. if you want a real test then hardwire your device, if you can't do that, then you should just change the channels and experiment.
channels 1, 6 and 11 are all you should use.
open a browser on any connected pc, and go to http://192.168.1.1
username is admin
password is the serial number found on your router
once you're in you click on change wireless settings in the first column and it takes you right to the channels. if you click on wireless at the top instead then you have to make one more selection which is basic security settings, and then you are at the channels.
change it to 1, and hit the checkmark for keep setting after router reboot.
the change would be immediate. if you don't notice a difference or it's worse, then change it to 6, and test. and then finally to 11 and test.
I think you will find one will perform better than the other.
if it doesn't then come back and let us know.