Core Dumps on 1.7.12 with SPDY

[numroo]

Hello

I'm running Nginx installed from the nginx.org repos on a Ubuntu Server
14.04.
There are about a dozen different sites running on this server, mostly using
PHP-FPM backend.

Since the update to 1.7.12 I had frequent core dumps (every few minutes a
series of two to four crashes).
I tried alot by disabling features, sites, config options without success.
The only thing I could tell, that two distinct sites seem to be generating
these crashes.
One running Wordpress the other running Owncloud. Other PHP-sites run fine.
No crashes as long as neither of the WP or OC sites are enabled.

Today, out of a hunch, I disabled SPDY on the two problematic hosts.

I had not a single crash anymore since then. 
But whats even stranger. SPDY is still active on those hosts.
It might be that SPDY is still actice due to shared IP & and PORT
configurations with other hosts on IPv4.
But I don't share IPv6 adresses between hosts.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,257977,257977#msg-257977