I wrote: > FB 5.5.1 has some minor incompatibilities with OS X 10.7 Lion. > > In settings >  Architecture must be Intel or Universal. >  In the Advanced drawer, the checkbox 'Use Compiler from Developer folder' must be ON. I should have said that this applies if you have obtained and installed Lion (but not Xcode 4) from the App Store. Your existing Developer folder is unchanged. Robert P.