First of all, I'm starting this thread NOT to make any argument, but as an intellectual-type discussion, because we had a brief in-game discussion about it, it was mentioned that an out of game discussion here on the BB would make sense, and because the traffic on the site is just too darn low!
Note: Steve, no need to make Rule Shrew comments, we're not shrewing here, just using the books as a guideline and deciding how we're going to do it. I think.

That said...
Critical: ...When your character scores a critical hit, roll the damage two, three, or four times, as indicated by its critical multiplier (using all applicable modifiers on each roll) and add all the results together.
However the following paragraph states:
Exception: Extra damage over and above a weapon's normal damage, such as that dealt by a sneak attack or special ability of a flaming sword, is not multiplied when you score a critical hit.
(There is also a critical hit section on P140 in the sidebar at the bottom, but it's the same wording)
I admit it is poorly written so as to beg the question, "What is normal damage for a weapon?"
I did some research for this same discussion online, and came up with the following:
here:
http://forum.rpg.net/archive/index.php/t-219792.htmland here:
http://www.giantitp.com/forums/showthread.php?p=7604849So from all that I'd say that Dan was correct and I was wrong; taking the comment from one of the threads I found:
As others have said, if it's a flat bonus it's multiplied. If it's dice damage, only the base weapon damage is multiplied.
To sum up: If it's a +x sword, the x is multiplied, as are strength bonuses and any other bonus that is fixed. If it's a special thing that does an extra 1-6 points, that damage is only added once, as is Sneak Attack damage and any other ranged damage bonus.
Flat bonus = multiplied. Range bonus = not multiplied.
Agree? Disagree? Commentary welcome.
* my apologies for being dimwitted last Saturday. On Sunday I found out I had a severe double ear infection. I now understand why children cry when they have them.