Yes, this bug still exists in Minecraft 1.4.4 pre-release. Please fix it, it's ruining animal breeding...
New stuff : this bug also concerns cobblestone walls.
This is also true for sheep, and perhaps for pigs too. I had noticed this bugs initially with fence gates just after the first official release of Minecraft and reported it on getsatisfaction, but I never knew if the report was ever reported to the Mojang team.
Yeah you're right, I was on peaceful ^^;