Could be the server OS setting.
This could be the problem: At one of my Tiki sites, on the Admin General page, I originally had the server OS set to "Unknown/other" and didn't have any problem with escaped quote marks. Then I set it to "Unix" 'cause I thought that was the right thing to do, and suddenly I get escapes all over the place. Then set it back to "Unknown/other" and the escapes stopped. So I'd say try changing that setting and see if the escapes continue.
-- Gary