The GRS is not the only storm on Jupiter.
Three storms were formed in the 1930s and were designated with the exciting names FA, BC, and DE. BC and DE merged in 1998 to form one storm, called BE. In March 2000, BE and FA merged to form "Oval BA," and that storm is, I think, what we are seeing in the GRS.
I think we are seeing a conjunction of Oval BA and the GRS. These two storms came together in July 2006.
I took the image below using the Slooh Telescope on February 24, 2007.
Although not as sharp as my recent photos of Jupiter, the GRS here seems to be larger, brighter and expanding into the southern regions, similar to today.
The problem with Oval BA is that my telescopes and the Slooh telescope in the Canary Islands usually can't detect it because its color blends into the surrounding atmosphere.
I'd love to see some images from some larger scopes.