As an incremental improvement over Bug 588419 when the SeaMonkey UI opens Data Manager to manage permissions or passwords (from tools menu or preference pane), it should switch to the relevant tab for the first domain with relevant data.
Created attachment 498651 [details] [diff] [review] v1: switch to first domain and and tab at load This should do it. Unfortunately, I can't run the test right now in SeaMonkey due to bug 619713, but it runs correctly in Firefox with the same changes in my add-on version.
Comment on attachment 498651 [details] [diff] [review] v1: switch to first domain and and tab at load r=me, I ran the tests by just changing all the "let" to "var" in the two files. Sorry about the delay in reviewing
Thanks, pushed as http://hg.mozilla.org/comm-central/rev/b99229f1b623 (and np, I wouldn't have been around much anyhow between when I requested review and now).