On Sat, 3 Mar 2012 01:22:35 -0800 (PST), robgraham wrote:

Any ideas - I've tried hot water and then the deep freeze without
success - maybe significant oven heat ?

You need differential temperatures between the two bowls, heating or
cooling both won't work. Try filling the inner stuck bowl with an
crushed ice/salt freezing mixture. If that doesn't work place the
stuck bowls in a larger container filled with hot (aka near boiling)
water to just below the brim of the outer stuck bowl. Give things a
few minutes to contract/expand.

--
Cheers
Dave.