As previously stated in one of the other posts, I mentioned that disabling the animations made the game run fine again. The issue though is that the game has always run devilishly smooth while them being on up until r141.
I've double checked my events, and there's nothing interfering with spawning of these objects (in fact they're always static and hand placed in the environment).
I also experimented with screen size, everything from 33 % size to 200 % in chrome didn't change anything, but 25 % and lower made the game run slower. However this isn't part of the real issue.
The game still runs 100 % smooth, except for when the player meele strikes (which is the core mechanic that triggers this animations). This has always worked flawlessly, except for the r141 update...
I also update my video card drivers. No change.
The reason why I doubt it is the sound at work, is that this slowdown is present also in layouts where I haven't touched ANYTHING since the last update.
If anyone wants to test out the last stable build the link can be found here: dl.dropboxusercontent.com/u/5323353/Klang12_8.zip