UIAutomation - WebKit Threading Violation - initia

Question

Running UIAutomation from the command line I often get:

WebKit Threading Violation - initial use of WebKit from a secondary thread.

Note, I'm using the -w flag and it's at the beginning. This answer didn't help: WebKit Threading Violation - initial use of WebKit from a secondary thread in UI Automation

Any idea how to avoid?

==== UPDATE

Just getting Instruments NOT to print this out would be useful.