Please recheck your firmware versions.
I think you are referring to
K.15.12.0010 , latest firmware september 2013
K.15.10.0016 , previous firmware (june/juli 2013?)
I am having issues with the K.15.12.0010 and finding this post I am also using trunks.
I haven't checked the load though.
What I noticed was the disability for any proper traffic on the switch itself (few KB/s) and no connection to the "outside" world at all.
The only "solution" was a reboot of the switch. After it had been rebooted everything works fine for a while, untill I started to (re)config. Then it would have the same issues.
When the switch is "hanging" eventually I got heart beat lost messages on module B. This occured with 2 different switches, both running the latest K.15.12.0010 firmware.
Reverting to K.15.10.0016 instantly solved everything and they are stable now.
I've adressed my issue to HP and will send them a link to this post aswel, for it might help to find a cause.