Andy, as you have figured out the "log" box needs to be checked under each individual spotter source to view the spots in that that window. According to Yuri the spotter(s) are still working but you cant see any visible activity if unchecked. I really don't see the purpose in this as I personally would always want them on.
The choice of naming "log" is confusing as its a different function than the "log" above on the telnet server. Hopefully Yuri will consider renaming this.
Glad you got it working.
Rich