What mode were shooting in; "24p"? ...60i?
Maybe that's what you see as flickering.. Canon's 24p is not true 24p and is progressive and interlaced frames in a 60i stream. ( i = "interlaced" )
This may only be an issue when viewing on a pc monitor, but TV should be ok.
Undoing this is called "pulldown removal"...
You can remove the pulldown with specialized software or a free method which makes you jump through so many insane hoops to get to the final result.
Interlaced video would look more like ghosting, but I am covering this in case you're using the word "flickering" to describe it and also being that you said it's an issue on your pc monitor and not your TV. (Which is characteristic of this issue.)
So, an easy way to rule this out (or in) is to set the camcorder to 30p and shoot some test footage, import to your pc and view on your pc monitor.
If it's the same thing as before, than the problem is something else. If it looks better than shooting 24p/60i, then you'll know that was the problem.
If that was, in fact, actually the problem; for your future videos always shoot in 30p, which won't have any issue on a TV or pc monitor (including for web delivery).