Have done some more debugging and I think the problem is that PHP is compiled in 32 bit mode, but when you compile on 10.6 modules by default get compiled in 64 bit mode:
file uploadprogress.so
uploadprogress.so: Mach-O 64-bit bundle x86_64
Get compiled GCC in 10.6.x
uploadprogress.so
uploadprogress.so: Mach-O bundle i386
Compiled in 10.5.x and are working.
I have uploaded a precompiled uploadprogress.so to try and help you out until we have solved this problem. The extension is tested and is working in MAMP 1.7.1, 1.7.2, 1.8.x under OS X ver. 10.5.x and 10.6.x.
Uploaded precompiled uploadprogress extension
Have done some more debugging and I think the problem is that PHP is compiled in 32 bit mode, but when you compile on 10.6 modules by default get compiled in 64 bit mode:
file uploadprogress.so
uploadprogress.so: Mach-O 64-bit bundle x86_64
Get compiled GCC in 10.6.x
uploadprogress.so
uploadprogress.so: Mach-O bundle i386
Compiled in 10.5.x and are working.
I have uploaded a precompiled uploadprogress.so to try and help you out until we have solved this problem. The extension is tested and is working in MAMP 1.7.1, 1.7.2, 1.8.x under OS X ver. 10.5.x and 10.6.x.