using version 13.0.509 mostly just updated to the current production build 13.0.547. locks up when i search for a node or crashes when I open the file menu.

I'm happy with 13.0.509 other than a few quarks. .547 was (after one run) working fine till it crashed but regardless it had those quarks fixed from 509.

As far as I can see when houdini locks up it doesn't show up as not responding but rather trying to using 13 out 12 processors if that makes sense. any idea why? if there is a way around this?

You might want to try the daily builds… it might be something specific to that build - or to your setup. Best way to test it is to try some other builds and see what happens. The fact that 509 worked ok leads me to believe that the production build may have some funkiness.