It flees as normal, not reproducible.
It does look a bit choppy.. Not sure if something can be done about this easily or why it is caused..
Confirmed on 1.4.2
I followed your steps exactly, and the potion wore off exactly after the 0:00 mark, as expected.
It sounds like your server isn't updated to 1.4.2
It's very clear this is something specific to your hardware. If your 5 year old computer can't support some of Minecraft's parts, you shouldn't run Minecraft on it.
This sounds like lag.
That has nothing to do with the login server, it means the server you're trying to connect to isn't being run properly, whether that means there's currently an issue and it's not accepting new connections, or it's not forwarded correctly, or even your internet is having some kind of issue connecting.
Not really a bug, and like Talven said I'm rather fond of this specific "bug".
This issue is not reproducible, and seems to be specific to your hardware.
Closing because this isn't a bug.
It is not possible to have the pig swim into water while riding it.
Confirmed on 1.4.2
Closing as duplicate.
You can keep feeding animals wheat if you want to, that's not a bug, that's the player's choice - it's not like the animal will only accept one wheat. In any case, after breeding, animals won't breed for 5 minutes.
This isn't a bug, and we don't allow feature requests. Closing.
Might you have a screenshot?