For those of you who can't get the upgrade to work, you're not being stupid.
There are various posts on the Adobe forums about this, so it's not you !
Here's a couple of responses from Adobe in their forums:
For some currently unknown reason the pages that folk outside of North America seem to be out of date. Until such times as they become fully accessible to all regions it's best that you use the FTP siteHowever if you follow that, you might not know which file you want.You can access all of the updates directly from the following FTP link ftp://ftp.adobe.com/pub/adobe/ (cut and paste into your browser address bar). Alternatively, if your browser supports clickable links to FTP then use Adobe FTP Site
This is the folder you need to look for: /pub/adobe/lightroom/win/1.x for a PC obviously.
This is the file you want LTRM_WWEFG_win_1_3.exe an obvious enough name.
These are the addresses if your browser supports FTP directly:
Mac
ftp://ftp.adobe.com/pub/adobe/lightroom/mac/1.x/LTRM_WWEFG_mac_1_3.dmg
Windows
ftp://ftp.adobe.com/pub/adobe/lightroom/win/1.x/LTRM_WWEFG_win_1_3.exe