[plt-scheme] How to navigate among split editors?

C-x o (control-x followed by oh).

Unfortunately, this doesn't seem to work quite right.  If I start DrScheme
and have an Definitions Window and Interactions Window, and split
Definitions (call the result d1 and d2), repeatedly hitting C-x o goes
in the following regular expression order:

d1 ; (d2 ; Interactions)*

Shriram

PS: Google Mail showed me sponsored ads for Hotels in Split, Croatia.