have performed a few updates
http://www.nearby.org.uk/blog/2007/08/29/flashearthgoogleearth-part-2/Executive summary:
1. The zoom is a LOT closer matched, thanks to a logarithmic formula.
2. Removed the title and the directions links, makes the balloon looks a bit nicer, couldnt get it to go transparent for me tho suggestions welcome.
3. When the network link is now a folder so can choose the size of your popup

The previous version is now the medium one.
Though the magic of the web, you get 1) and 2) automatically, if want 3) just download it again:
Open in Google Earth (Required: GE 4.2+ Windows)