Hi Nick
I've never encountered this but I suspect you are right and the window
is being restored to the no longer existing position when you reopen
the application. So you could delete or edit the qgis settings file
which off the top of my head is under /Users/Library/ in the
applications
One last thing. Not sure if its my browser (Firefox
2.0.0.1+dfsg-0ubuntu0.6.10 (edgy-security)), or how my browser is
configured to download these data types, but links to checksum
(http://download.qgis.org/qgis/edgy/qgis_edgy.tar.gz.md5) and torrent
files