I recently did the move posts to pages thing, I'm a new user trying to learn my way around WordPress, but I found the all of the comments I moved over still had my user avatar even after I changed the user information. WordPress just didn't want to acknowledge the user information I put in as the originator of the comment.
What I finally found that I had to do was to make a copy of all of the comments along with the relevant data of the data and original poster. Then log out of WordPress as administrator and re-post all of the comments as an outsider user. Then WordPress recognized all of the comments as they correct person. Then I logged back in as administrator and edited the dates back to the originators dates. This is a pain in the butt way to do it, but it works like a charm. This is just one of the many problems that I'm finding with the way WordPress does things. WordPress is easy so long as you don't have to make changes, but it becomes a bear when working between Pages and Posts. I'm starting to wonder why didn't the programmers of WordPress include the same features that exist in the Pages area into the Posts area. That would permit Posts to be segregated like in the Pages area. In fact I don't even under stand why there is a separate Posts and Pages area when this is totally necessary. There is a block in the thinking of web log creators that you need to have a separate blog for each subject. Both the features in the Posts and Pages area can be and should be combined and if necessary with switches to turn off the features that you don't wont.
WordPress is not a easy as advertised, because some one didn't think that someone would want to do things a little differently. I'm figuring out ways to get it done, but it could be made a log easier by the WordPress programmers. Now my big battle is how to get the tags function in the Posts to work with the Pages to attract attention to my stories. If anyone is interested in the way that I'm doing my blog, go to http://mntornado.wordpress.com and take a look around. I've created a multi-themed blog that allows me to post all my stories in one area with out having to log out and back in again to multiple blogs.