Well, I don't know. I tried several settings in the virtual machine and nothing seems to work. I tried then the Keynote preferences. Still nothing at the level of editing, the slides remain blank, but something unexpected happened. While Keynote reported that it was not possible to play the slideshow because of too little video memory, which was not, it would let me nonetheless to rehearse it (which confirms that the video memory was more than enough). After activating the option "Allow Exposé, Dashboard and others to use the screen", the slideshow could play without problems! And this option is supposed to decrease performance.
But there is worse. I tried to take some screenshots with the usual key combination ctrl + cmd + 4. VMware reported that CPU has been disabled and this triggered a kernel panic which I could consistently reproduce. So it seems that my problem is related rather to the CPU than to the video memory amount or 3D acceleration.
As to 10.6.8 being ancient, what Windows 7 or Windows 2000 are? Aren't ancient too? However, they are perfectly supported in VMware. I guess that Mac OS X guests did not get enough attention, which is not exactly in line with the price target of Fusion.
