[Exim] Exim 3.36 and RBL

I've been poking around much of the day trying to find an answer to this
oddity, without much luck. We are currently using 3.36 and filtering with
the following RBLs:

spamsites.relays.osirusoft.com
spamhaus.relays.osirusoft.com
spews.relays.osirusoft.com

When attempting to whitelist certain senders using

mail.hostname.tld/accept

exim still rejects the mail if the sender is listed in one of the three
filters above. According to the specs, if an /accept is reached for a
matching domain, no further checks are completed and the mail is delivered.
That does not seem to be working very well here. Note that at this time,
moving to exim 4 is not an option. If anyone could shed some light on these
rather bizarre happenings (or just a sample of a known working config), we'd
appreciate it.