eye - first, welcome to the forums - what part of the country are you from?
besides the line and fluid, have you recently performed any other brake maintenance? how old is the bike?
since non-synthetic brake fluid absorbes water, it is not uncommon for there to be a build-up of "crap" inside the caliper (behind the seals) which causes the caliper piston to stick after pads have been replaced (push the piston back into the crap to get the new pads on).
Anyone else have any thoughts?
The first tool out of the box should be the "book"