I am using gedit 2.91.8 and if I close tab using ctrl+w not the "following" tab is selected, but the second to follow the closed one.
This happens on Fedora 15 alpha / updates-testing.

An example: I've got the tabs "a", "b" and "c", "a" is active:

[a] / b / c

If I close tab "a", tab "c" get's selected not tab "b":

b / [c]

(Selected tab is in [])

I use to navigate using the keyboard. Also selecting "b" and the selecting and closing "a" warps me to "c".