When I debug the project in visual studio, (connecting to localhost) it works fine.

When I deploy the project to our live server however I get Sys.WebForms.PageRequestManagerParserErrorException thrown by javascript on the client when I try to use the "Print this topic" or "Email this topic" choices from the options menu.

When I did a google search on this error it says the most likely causes are tracing, (that is off) and calls to Response.Write() (doing a search of my entire project both the sitecore and the YAF code reveals that that is only called in 2 locations, default.aspx, (that should really never be called) and \sitecore modules\Web\YAF\admin.aspx but I'm not in the admin section when I'm having the problems so that shouldn't matter either.

If I use the email button on a specific message in the topic it works and as far as I can tell that updated the same part of the page as the options menu's "Email this topic" should, (although the email it generates is different.)