[Fixed] Upgrade already researched, still shows up as available

[John.d.h]

Code: [Select]

[URL=http://imageshack.us/photo/my-images/560/screen28.jpg/][IMG]http://img560.imageshack.us/img560/115/screen28.th.jpg[/img][/URL]
As you can see, the upgrade has already been researched but it is still available to click on again.  When I clicked on it again, it gave me "order invalid" or something like that.

Commit 7b8a7e

[hailstone]

Cheers. I've committed a fix in fd6ce61..