People who have no prior experience of wikis tend to think an author owns a page and do not dare to change the content. Rather than that they write eMails or Comments or offer their input to the author over lunch or coffee.
You start hearing complaints from the early adopters, e.g. that wiki authoring is too much work - that it takes too much time to incorporate other people's input. Alternatively you hear complaints from the early majority that a wiki author is “unresponsive” to other's material or ideas, or that the material is “not accepted”. When you ask for a specific story or details, you get to hear about wiki-related feedback received or sent through non-wiki channels or through comment/talk pages.
Ask anyone describing something that sounds like PageOwnership “did the person who suggested this appear constructive to you and did they offer to edit the page her/himself?” and “did the author react positively and suggest that (s)he go ahead and Be Bold?”. Be prepared to explain and/or confirm that wiki is non-territorial and that changing another person's text is fundamentally a Good Wiki Thing (TM?).
Every time influential individuals or a large or strongly interconnected group join the wiki, hold a hands-on training session, where everyone gets to edit real, valuable material authored by the trainer (who has to have solid self-confidence and not take any changes personally). Attempt to create as many problem situations as feasible during the training and help the learners create mental models for how they can solve/survive them.
The Champion creates a page, but no one in the project dares to correct the spelling mistakes, because it is seen as her or his own page.