Wordpress 3.0.5 seems to have a problem with inserting photos into pages. Link to bug I'm not too familiar with the internals of Wordpress, so it looks like the blank page that shows up when you click the "Insert into post" button is trying to use javascript to push the a and img tags back to the editor, but just ends up failing. Some of the references talk about outside libraries having incompatibilities. I'll have to dig into that.
Part of it is probably because I switched from running Debian testing to Debian stable. This has been the only issue since the switch.
Last resort is to replace the package with the sources from Wordpress.org I might test out switching out to the latest version and see what happens.
Update: 2011-11-28: The problem was that the jquery library was 1.6 and WP was expecting 1.4. Downgrading the package fixed the issue. (From libjs-jquery_1.6.4-1_all.deb to libjs-jquery_1.4.2-2_all.deb)