I've uploaded a capture.
Idea : it could be that you've installed the LRG files in the templates
folder and not in the galleries
The gallery folder is as follows :
Users/username/Library/Application Support/Adobe/Lightroom/Web Galleries/
On Windows XP
C:\Documents and Settings\username\Application Data\Adobe\Lightroom\Web Galleries\
On Windows Vista
And note that's it is named Web Galleries
, and not as its neighbour Web Templates
If I'm right, close LR, cut all the LRG XXXX subfolders in the templates folder and paste them in the galleries one (NB if there is none, create one), and restart LR.