cannot access to any site with ssl connection and fail to open safari and keychain, unless restart computer and login in with Guest account.

Same problem here too and with 5 other colleagues. Lets hope Apple are working on it.

I also have the same problem, however if I use Firefox or Opera sites with ssl connection work fine. Still, I can't use Google Chrome (ssl), Safari (ssl), the Mac app store (generally), or the iTunes store (generally). Both the iTunes store, Safari and the app store won't respond, and Chrome displays this error: (net::ERR_TIMED_OUT). The problem persists regardless of what network I'm using. Also, when trying to access the keychain or iCloud, the process will not start (will hang). I didn't have these problems at all before updating to 10.7.2.

Sometimes rebooting helps, and sometimes not. If the problem disappears by rebooting, then it only lasts a few minutes before it reappears. It is very frustrating, especially since there doesn't seem to be any obvious or consistent way of which to fix it.

I'm also using a Macbook Pro 13-inch mid 2010.

Run disk utility and repair disk permissions then verify permissions, after that boot into your recovery by holding command R on start up once the window apears choose disk utility and repair disk then verify, reboot and see if that was the problem.

I followed your instructions, but unfortunately it didn't do the trick. Thanks for the tip anyway, though!

I have this problem when I try to connect to my school's WiFi. Their network redirects you to a page to authenticate before you can access the Internet, and it seems like this is causing the problem. Other people had similar issues in this thread:

http://forums.macrumors.com/showthread.php?t=1249903

Both Safari and Keychain Access crash (and anything else that tries to access an SSL page through the native networking code, such as the App Store) after I try to log on to their network, and Chrome simply times out. For now I've had to revert back to 10.7.1, but I'd really like to know if there's a fix for this.

Thanks for the reply. Regarding your theory about authentication problems being the culprit - unfortunately I also get the same problems when using WiFi at home. Do you only experience problems when using your school's WiFi?

One of the first things I tried was to erase my drive and restore from a 10.7.1 Time Machine backup, then upgrade to 10.7.2 again. It didn't work.

However, I seem to have fixed the problem with a little more drastic measure. I reinstalled Lion from a clean drive without a full restore from the Time Machine backup. Instead, I only restored my Home folder, my Applications, and my preferences when I was asked to during the Lion setup. After that, I upgraded from 10.7 straight to 10.7.2 using the combo update. Now I have no problem connecting to my school network.

This solution does seem a bit drastic to me - how do I perform a clean install without losing my personal data? Did you first erase your disk and then install Lion from scratch? Thanks.