It becomes more likely the lower the tyre pressure you're running as the rubber can flex.
I see you've had a recommendation from Google for 10j rims for a 32" tyre - sounds like the usual problem of Google, you've got a general answer to a query that is very specific as it depends COMPLETELY on the specific tyre size and the tyre manufacturer's recommendations.
10j for a 32" must be a very wide tyre you're looking at Doug as the 33s on my old Trol were fine on 8j rims (manufacturer recommendations) and I suspect the 4.2 will be on 8j as well (it's also on 33s).
What's the actual size you're looking at? ie. It's it 265/75 16 or something else? What brand and type?