Your last post shows in fact the event is not happening. Dalnet is sending a different message.
I tried several different networks, and of the 4, only SwiftIRC shows the ping/pong message when that option is unchecked, because that's the only one that's actually a PING.
<- PING :conclave.il.us.SwiftIRC.net
<- :bitcoin.uk.eu.dal.net PONG bitcoin.uk.eu.dal.net :TIMEOUTCHECK
<- :livingstone.freenode.net 303 My$nickGoesHere :
<- :irc.underworld.no PONG irc.underworld.no :TIMEOUTCHECK