I have managed to get to around 1900 before I get corruptions. I am starting to wonder if it is a memory leak or some other form of memory allocation bug in the Mac version of Rocksmith or if the patch in combination with the original causes some form of memory corruption. I can easily load up to 1900 in the first enumeration but going back to the boot screen and performing a second enumeration (the workaround for missing CDLC) will cause blank album art and loss of all songs. Renumeration will work if I have a number of songs bellow around 1600-1800 but cause errors if I have more songs. So maybe its the transit to 64-bit that's the cause (again :-))