AFAIK, the only real way to bypass that problem is to 'hack up' the configure script to give it proper values when it can't run the test program. However, in cases like this, I have always moved on to building with the native compiler on the zaurus, as it becomes a HUGE pain to deal with when cross-compiling.
However, if you DO move to the native development environment, I definitely suggest the use of distcc. Since you already have the cross environment setup on your desktop, simply install distcc, and from within your x-compilie env (ie: after running runzgcc.sh), run the distccd server. Make sure to link gcc, cc, g++ and c++ to their arm-linux-* counterparts in /opt/arm/3.3.2-vfp/bin. That way, distcc will use the proper compilers.
On the zaurus side, you need to install the distcc package from the rc5 feed, then make a new directory anywhere that will contain links for gcc, cc and c++ (don't THINK I'm missing anything here, but I could be...) to /opt/sdk/bin/distcc. Add that new directory to the beginning of your path, set your DISTCC_HOSTS, and off you go Compiling is at least 5 times faster, I've found, using distcc on the zaurus than just having the z compile by itself.
Dave