I've recently downloaded the (beta?) 5.1.8 version of Max (from the Ableton link), and it has lots of problems loading old max4 patches (I have 16 years of max v 2-3-4 patches! didn't have time to translate them all...).
F.i. many cables are messed up and it doesn't seem to recognize the preset object: the attached simple m4 patch doesn't work in 5.1.8, but does fine in 5.1.7.
btw. is it safe to have two different versions of max5 on a computer?
macbook pro 2.8 ghz core 2 duo, osx 10.6.6