Use the new BST dictionary for indexing members.

src/members-payments.scm

@@ -98,10 +98,9 @@
 		(varsym-id (transaction-extract-member-id transaction))
 		(bmember (find-member-by-id mb varsym-id)))
 	   (loop (if bmember
-		     (mbase-update
+		     (mbase-update-by-id
 		      mb
-		      (lambda (mr)
-			(compare-member-id (brmember-id mr) varsym-id))
+		      varsym-id
 		      (lambda (mr)
 			(brmember-add-payment mr transaction)))
 		     (if (and (or (not last-checked)