Comment 11 for bug 209848

I can confirm this bug.

This only happens with thunderbird, and when I call the old firefox2.

The effect is that on my laptop (Asus A8JS) the thunderbird window is shown on the left display (I have a monitor attached right of the laptop, so left is the laptop screen) in fullscreen, with no borders. Im not able to move or resize it in any way.
When it happens, then every child window (e.g. reply) has the same effect. When it doesn't happen, (because it is temporarily fixed by the workaround below) every child works except that sometimes when writing a reply the window borders flash to full transparency and back with every keystroke :)

A temporary workaround can be found in this post:
http://forum.compiz-fusion.org/showpost.php?p=59083&postcount=13

It states:
--- SNIP ---
Located in your ~/.mozilla-thunderbird directory is your default profile directory. There is a file in there called localstore.rdf that specifies settings in XML. Edit the file and check out the tag that starts with:
<RDF:Description RDF:about="chrome://messenger/content/messenger.xul#messengerWindow"
You should see values for screenX and screenY (that are the coordinates of the upper left corner of the Tbird window). Set them to something like 5 and set width="800" and height="600". Save the file and restart Tbird and see if that doesn't fix things.
--- SNIP ---

But usually after about 2 or 3 starts of thunderbird the problem is back. Couldn't find a pattern here yet.