Can't switch users or log off since upgrading to Mavericks

I had that same issue once with an older OS, it would disconnect from the wireless whenever I switched users. I'm not sure what happened but eventually it went away.

And this morning the switching worked well too, both ways. Not sure why but I think that's the first time since I installed Mavericks. Hope it stays that way.

Yes, I'm having the same problem -- on both my 27" iMac and MacBook Air. I installed Mavericsk on both a couple months ago and immediately noticed that switching users is no longer quick and seamless like it was on Mountain Lion. The little black spinner comes up and it takes about 45 seconds to switch users, and sometimes it doesn't switch at all and the screen just goes grey. Then I have to reboot. I have no idea how to fix this, but it's remarkably annoying because we have multiple user accounts on both of these computers.

Well, as I said above, I restored my Mini and 13" MBP to Mt. Lion. Having seen little in the way of "can't live without it" features in Mavericks, I'm waiting for the .2 or even .3 updates to 10.9 before I try it again. And my plan the next time will be to execute a wipe and clean install for the OS followed by fresh installs of all of my apps.

Having heard relatively few complaints from users of new machines, I'll follow the assumnption that it's the upgrade that may be at the core of these problems.

Thanks. My buddy has a brand new iMac that came with Mavericks and he has no problems switching users. I agree, it's probably the upgrade. The problem is I don't even have a copy of Mountain Lion. I paid like $20 a year or so to go and it downloaded to my computer and installed itself. I don't have a CD-ROM of Mountain Lion. I would happily go back because there's nothing about Mavericks (which was a free download) that I find better the Mountain Lion. I'm sure there are features but I don't use them or know about them. You know it's strange, ever time I've updraded the OS with my Macs over the years I almost immediately regret it. There's always something that doesn't work. Even with Mountain Lion, my scanner mysteriously stopped working. I went to Canon's website, tried downloading various drivers and such, and still wouldn't work. Took me about a year to fix that one Oh yeah, BTW, with Mavericks, trying to logout a user takes a long time too. The screen just goes white for about a minute before it finally logs out. Sometimes it takes longer and I just say to **** with it, and hold the button down to turn the computer off. This sort of crap is why I stopped using PCs years ago. Hate to see annoying stuff like this with Apple too.

I've been a Mac user since '85, and this is the first time I've ever encountered a problematic OS upgrade.

It sounds like you don't have any kind of backup? You really should have an external HD and let Time Machine backup your entire system once a day. All I had to do to get back to Mt. Lion was restore my previous system from the day before I installed Mavericks. At the very least, you should always backup your drive prior to an OS upgrade.

Actually, I do use Time Machine. That's a great idea. Thanks.