Solid Difference fail w/near-tangential faces

Hi,

I'm having a problem calculating Solid Differences - my two breps intersect at a point where the intersecting surfaces are almost (but not quite) at the same angle. This is causing an open intersection curve and the intersection to fail, so SDiff just gives up and doesn't intersect anything, and returns one of the original surfaces (which should have a hole through it).

I've done the operation using Rhino (without grasshopper) and the same thing happens, an open curve intersection is generated and booleans fail.

The Rhino FAQs on the subject indicate that there isn't really a proper solution to thisat the moment: http://wiki.mcneel.com/rhino/booleanfaq

Has anyone had this problem/found a way to fix it? My current thought is to scale the surfaces so that the intersecting angle is greater (and then reverse the scaling of the result), but was wondering if anyone had found a cleaner way around this!

Thanks

P.S. for a number of reasons i am unable to upload my grasshopper or rhino files, this is really more of a conceptual problem than a specific one!