Another dumb question from a newbie: multiple bugs on the same page = 1 bug?

[ninetydegrees]

I keep finding bugs on Manage Comments. I've already filed three and I could file two more. I'm afraid it's getting a little ridiculous. What's the policy in this case? Should I file the new bugs independently anyway, edit the last one and give it a vaguer title? What?

BTW are there any guidelines somewhere for using Bugzilla? I don't get when it's ok to reopen a bug and when it isn't for example.

A: Reopen when there is a problem with the fix itself: it didn't fix the bug.