The dock crashes +/-5 minutes after reboot

Question

As of yesterday, the dock simply crashes +/- 5 minutes after reboot.
I've been running SL successfully since the day it came out, without any problems.
I did upgrade an application, DockStar and feel that's the culprit here, although I have been running a demo version of it successfully.
If I go to system preferences and choose Dock it takes a while before the dock pane shows up and with default settings, and it also acts very slowly when changing settings. If I change the settings and then close the system preferences and then reopens it then my settings have disappeared.
And the bigger problem is that the Dock can not be seen (and it is not hidden at any of the monitor edges either).
How I can restore the dock?

Answer 1

Kenichi Watanabe wrote:
Did you try moving the Mail preferences file to the Desktop (when Mail is NOT running), so that a new one gets created (by the Snow Leopard version of Mail.app)? That preference files is here
<user home folder>/Library/Preferences/com.apple.mail.plist
I just did it myself, and it did not change anything related to your accounts or what's in your Inbox, but the Mail windows size went to the default size and look. It did says say my "Outbox" has been renamed "Delivered," which is odd because it did not do that before when using Mail in Snow Leopard. If you drag the preference file to the Desktop instead of trashing it, you can put it back if something important is changed in Mail that you want back.
I just tried moving the Mail preferences file to the Desktop (I also got that odd Outbox/Delivered message), and the Dock indeed doesn't crash now.
BUT, I did loose all my accounts, so I had to drag the original preference file back.
Some extra info: The clean generated com.apple.mail.plist is only 8KB, while mine is 45KB.
Another fact: I only started using Mail for the first time after the Snow Leopard upgrade (because I'm an Exchange user), it's not that this has been an upgraded Mail with old accounts or settings in it.