That's correct, it should only be connected to one pin or it will malfunction. According to the description in
http://ftp.sunet.se/~aminet/dirs/aminet/hard/hack/2MegAgnus50d5.lha "you must connect the clip lead to pin 36 of the GARY chip or pin 48 of the 68000 chip". I think it's best to connect it to the Gary chip, since any accelerator would disable the 68000. Or maybe it doesn't matter.
/Martin
