Many settings pages have very little error checking. You can easily alter a setting which will result in a non-functional system, and short of restoring the database from a backup, there is no way to undo your changes.
Edit settings for: MythWeb Session
Recorded Programs:
Download URL override: file://
Page recorded programs:
Guide Settings:
Only display favorite channels:
Max star rating for movies:
Star character:
Timeslot size: minutes
Number of timeslots:
Group timeslots every:
Rows to show between timeslot info:
Date Formats:
Status Bar: 
Upcoming Recordings: 
Scheduled Popup: 
Recorded Programs: 
Search Results: 
Listing Time Key: 
Listing "Jump to" 
Channel "Jump to" 
Hour Format