After running the 10.5.6 updater, I had two bad problems, my Mail went sideways, and my menubar clock could not remember what timezone I set it to. The Mail problem I fixed with an update from Apple, but the clock I fixed myself - here's the fix if anyone else experiences this.

The Date&Time settings do not stick, i.e., you set your time zone (GMT-5 in Ottawa) and as soon as you leave the Time Zone pref pane, it sets back to plain GMT, i.e. it says 9:00 when really it's 4:00! Here, then, is the fix. If you're not comfortable with the terminal, this may be a bit scary, but it works.

Quote1. Open the Terminal program from your Utilities folder.
2. Type the following exactly:
sudo mv /etc/localtime /etc/localtime.old
3. After you press return, you will be asked for an administrator password and reminded that what you are doing could be dangerous (it isn't). Enter the password (nothing will appear as you type your password - that's normal) and press enter.
4. Quit Terminal, Restart your Mac, and reset your time zone in the Date&Time System Preferences. Everything should now be normal!
5. Optionally, you can remove the localtime.old file you made in the step 2. To do so, crank up the terminal again (hey, you're getting good at this!) and type the following:
sudo rm -d /etc/localtime old

Hope this helps - it drove me crackers for the first few days.

Happy Mac'ing

Dan