Thanks Kent and Ian, I just did a few things. First I installed Mono on top of what had already been installed. That went fine, but it didn't change the behaviour of Control:Mac. Then I decided to get rid of all traces of both Mono and X11. So I dig some Googling and found a script to enter into the command line for removing Mono. X11 was easier to remove thanks to AppCleaner. After that I restarted the computer and repaired permissions. Alas: same result.

Just in case someone is still willing to dig through this, below is the new problem report up to the Binary Images section. For me though, this is it for the Mac, and I will just get my Windows machine replaced. Thanks everyone thus far!

Process: ControlMac [442]
Path: /Applications/ControlMac.app/Contents/MacOS/ControlMac-SystemVersionCheck
Identifier: com.Sooloos.ControlMac
Version: ??? (???)
Code Type: X86 (Native)
Parent Process: launchd [144]

Date/Time: 2012-10-23 21:06:08.554 +0200
OS Version: Mac OS X 10.6.8 (10K549)
Report Version: 6

Interval Since Last Report: 19577 sec
Crashes Since Last Report: 6
Anonymous UUID: 8BDB7FDC-0DBB-4370-B6B4-E49C1611B538

Exception Type: EXC_BAD_ACCESS (SIGABRT)
Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000000000000
Crashed Thread: 3

Application Specific Information:
abort() called

Thread 0: Dispatch queue: com.apple.main-thread
0 ControlMac 0x00152cad mono_jit_info_table_find + 405
1 ControlMac 0x0000dafe mono_sigsegv_signal_handler + 255
2 libSystem.B.dylib 0x9230305b _sigtramp + 43
3 ??? 0xffffffff 0 + 4294967295
4 ControlMac 0x0000dafe mono_sigsegv_signal_handler + 255
5 libSystem.B.dylib 0x9230305b _sigtramp + 43
6 ??? 0xffffffff 0 + 4294967295
7 ControlMac 0x0023251b mono_once + 154
8 ControlMac 0x00228988 _wapi_handle_new + 98
9 ControlMac 0x0023803e sem_create + 69
10 ControlMac 0x00238645 CreateSemaphore + 129
11 ControlMac 0x001fed9c mono_thread_pool_init + 169
12 ControlMac 0x00121015 mono_runtime_init + 32
13 ControlMac 0x0000f192 mini_init + 3782
14 ControlMac 0x00096232 mono_main + 5387
15 ControlMac 0x00002b23 main + 371
16 ControlMac 0x00002476 start + 54

Thread 1:
0 libSystem.B.dylib 0x9229cafa mach_msg_trap + 10
1 libSystem.B.dylib 0x9229d267 mach_msg + 68
2 ControlMac 0x0011ffd2 mach_exception_thread + 81
3 libSystem.B.dylib 0x922ca259 _pthread_start + 345
4 libSystem.B.dylib 0x922ca0de thread_start + 34

Thread 2: Dispatch queue: com.apple.libdispatch-manager
0 libSystem.B.dylib 0x922c3382 kevent + 10
1 libSystem.B.dylib 0x922c3a9c _dispatch_mgr_invoke + 215
2 libSystem.B.dylib 0x922c2f59 _dispatch_queue_invoke + 163
3 libSystem.B.dylib 0x922c2cfe _dispatch_worker_thread2 + 240
4 libSystem.B.dylib 0x922c2781 _pthread_wqthread + 390
5 libSystem.B.dylib 0x922c25c6 start_wqthread + 30

Thread 3 Crashed:
0 libSystem.B.dylib 0x9230a0ee __semwait_signal_nocancel + 10
1 libSystem.B.dylib 0x92309fd2 nanosleep$NOCANCEL$UNIX2003 + 166
2 libSystem.B.dylib 0x92384fb2 usleep$NOCANCEL$UNIX2003 + 61
3 libSystem.B.dylib 0x923a66f0 abort + 105
4 ControlMac 0x000bd8ab mono_handle_native_sigsegv + 324
5 ControlMac 0x0000dae0 mono_sigsegv_signal_handler + 225
6 libSystem.B.dylib 0x9230305b _sigtramp + 43
7 ??? 0xffffffff 0 + 4294967295
8 ControlMac 0x0022b6e6 _wapi_handle_update_refs + 401
9 ControlMac 0x00225511 collection_thread + 52
10 libSystem.B.dylib 0x922ca259 _pthread_start + 345
11 libSystem.B.dylib 0x922ca0de thread_start + 34

Thread 3 crashed with X86 Thread State (32-bit):
eax: 0x0000003c ebx: 0x92309f39 ecx: 0xb01889fc edx: 0x9230a0ee
edi: 0x00000000 esi: 0xb0188a58 ebp: 0xb0188a38 esp: 0xb01889fc
ss: 0x0000001f efl: 0x00000247 eip: 0x9230a0ee cs: 0x00000007
ds: 0x0000001f es: 0x0000001f fs: 0x00000000 gs: 0x00000037
cr2: 0x00000000

Rowland Model6/BPS6, Rowland Coherence II, Levinson 390S and 37, AudioAanZee Reference Flow music server, Rowland Aeris DAC, Rowland Cadence phono stage, Pass Labs Xono phono stage, Yamaha PX-2 and Thorens TD 160MKII, Transparent Ultra and Reference cables, Apogee Diva magnetostatics (refurbished).