www.ultimatehandyman.co.uk

as lond as your edge you wish to profile is "smoothe" (without dents imperfections in the line the bearing will roll along), the bearing will follow it without reproducing the errors on the profile part your trying to make into a nice finish, even so a quick sanding will soon loose the imperfections or burn marks... if you get burn marks push the router a little faster that should cure the problem. usually a sign of blunt cutters but can also be pushing too slow and the resin + dust being heated in the same spot by the cutter rubbing it. hard woods and mdf are classic for it.

If i get burns i normally drop the cutter just a faraction, so almost no material is removed, then whip round again.

yep same as that Hitch, but knowing the reason is part of the way to knowing the cure, helps prevent same issue futher along the same job ;)

Quite right. Corners seem to be the worst places for it.