NOT FIXED
THIS IS NOT FIXED. (At least not in 1.8.5)
The "amp" has been removed, however, the semicolon ; has been left in.
In config.php, you need to go to the 'galaxia_execute_activity' function defintion at the bottom. Look for this line:
$parts[count($parts)-1] = "tiki-g-run_activity.php?activityId=$activityId&;iid=$iid&auto=$auto";
You have to remove the semicolon right after "$activityId&".
Frankly, I'm somewhat stunned that a bug that completely breaks automatic activity processing has been left unfixed in the "stable" build for so long. I mean, not even the trivial example in the manual works because of this!