Sure, I got flamed for reviving a Transmission bug (torrents would not start from the watchdir, they would get added as started but no peers would connect). It was a "known bug". Known for about two years then. Must have been some really nasty thing, if nobody could fix it during two mayor versions.
And for Ubuntu, I reported message indicator not working properly with Empathy - its one of the nicest features in Unity. "It regressed". They will fix it in 12.04. Maybe. A bug has to wait half a year, because the package is frozen. I wonder if they do the same with security holes. And don't start me on the LTS version ;> Many fixes come with next Ubuntu version. This makes LTS versions pointless. (since they're as bugged as any other version)
Oh, and I shouldn't need to report bugs, Ubuntu has no bugs. Its open source, the all-knowing community squashes bugs in the planning stages.
But... To be fair, after trying 12.04, it is the best Ubuntu alpha I've ever seen. And Ubuntu+1 IRC channel activity would suggest its a smooth ride for other people too, so far. Although, they did not fix the Empathy bug, I have high hopes for it.