Your contending that dwarves and elves are more powerful than humans? And half-orcs?
I would have to agree with the earlier post that humans are the most powerful race. Think about it. 4 extra skill points at level 1 and 1 extra thereafter every level. Any class is considered it's favored class. An extra Feat at 1st level. That's the gift that keeps on giving, man!
Each of the other races has their cool perks, yes. IMO, though, none of those cool perks overbalances those that humans get. It's pretty darned balanced. And makes it more a matter of role playing opportunities and customizing a character concept.
"Weak" is a very objective term for any of the races. It's based entirely on your perception and personal experiences with them. I've seen players with halfling characters that outshone every other character and race around a gaming table because the player knew exactly how to get the most out of that halfling. The same has applied with half-elves, half-orcs, humans, and all of the rest. It all depends on what you're trying to get out of it.