Ok I found "You have been Summoned!" offset and can block that, but can't seem to find "You will not evade me %1", so you get 1/2 summoned, meaning you appear to not have moved but the mob will beat the crap out of you. Maybe later I can use tsearch and figure out where that part is called from.
[Nosummon]
Description="NoSummon sort of"
Version="2006.02.23"
address0=47ABED
normal0="0F 84 43 42 00 00"
crack0="E9 44 42 00 00 90"
I recompiled the nosummon plugin if that helps, and it still works (probably a safer bet):
http://www.redguides.com/community/showthread.php?t=8019