You shouldn't have problems using gcc4 to build the modules. As long as when you change to using gcc4 from gcc3 you Rebuild All Modules, you'll be okay.
The reason there are problems with the two versions is that the GCC guys changed the internal vtables in gcc4 so that you can't link code from one to the other - for static-compiled apps, that is a Build-time issue. For Apps that used shared objects you need to have the compatible .so's on your system. (note that original warning about libstdc++)
The reason there are problems with the two versions is that the GCC guys changed the internal vtables in gcc4 so that you can't link code from one to the other - for static-compiled apps, that is a Build-time issue. For Apps that used shared objects you need to have the compatible .so's on your system. (note that original warning about libstdc++)