Apparently Spaces isn't quite polished up yet: Apart from the bugs that some people here have already reported that their programs keep appearing in the wrong space, or simply dont remember in which space they should open up, I have encountered another bug, which is really troublesome: If you have like 4 spaces and you have Safari let's say in Space 1, and keep working in space 4, then when you click on the safari dock icon, spaces automatically moves over to the 1st space. Well after some time it doesn't do that at all. You can keep on hammering safari's dock icon but to no use at all: Spaces wont move. It gets even worse: The windows of safari (or any other program affected by it, even textedit had this prob with me) just become invisible alltogether and are not accessible at all in any space. The only remebed is to turn off spaces and turn it on again in system preferences.