I am running 5.0.DB46000000.3084 2008-05-05 and would like to do a
software update to the latest version. However I can't see how to do it exactly.

Under MAINTENANCE -> software update it says

System software update
1. Apply update

Info
Update complete.
Press reboot to start from new system.
Reboot from new system
* Copy current settings

That all looks fairly obvious, but it doesn't give ANY info on what version it is
about to update to. I don't recall manually uploading an update.

How can I tell what version it is about to update to. There seems to be no
option for me to upload an update. The instructions mention an "Update downloader"
section. I can't see this. It doesn't seem very sensible to blindly update to an unknown
version.

Any help appreciated.