Is there any outstanding reason XtVaCreateManagedWidget might hang the entire system while it runs?

I have a program that slows the entire system down to unusability about 1/5 of the times it is run. Of that 1/5, about 1/3 of the time everything eventually (between 30 seconds and a few minutes) picks up again and it is usable, 1/3 the program/gnome-terminal quits or the system logs out, and 1/3 I have to manually restart the (virtual) machine.

I have tracked down the problem to XtVaCreateManagedWidget, and run over it a lot. Sometimes it runs fine, sometimes it takes a while, and sometimes it crashes the debugger. I should note it is looped over about 30 times where the problem occurs.

I have seen things vaguely like this by google searching, but they all seem to be closely related to going from 32 to 64 bit.