Sleep but no resume

[edjabr@gmail.com]

Running stable 64bit with the 3.2.65-1+deb7u1 kernel.  This macbook 
will go to sleep but will not resume, requiring a hard reboot.  When 
s2ram is run, the acivity light blinks- a sign that the machine is 
really asleep.  However, when I hit a key, the light goes out and no 
resume.  

I booted into OSX and sleep/resume was flawless, so it’s not hardware.  
Resume worked before the recently updated proprietary nvidia driver. 
So, uninstalled it and ran with nouveau, but still nogo.  I then 
installed a newer proprietary from backports.  No resume still, so it 
doesn’t seem to be a driver problem.  I've googled a lot and looked 
through files I never heard of before but couldn't find anything 
helpful. Bug #774461 refers to a fix for a similar but really 
different problem, and says that sleep/resume is fixed with the kernel 
I’m already running.  I’ve run s2ram wth different parameters but got 
nowhere.  Finally, s2ram --test returns 

 Machine unknown
This machine can be identified by:
    sys_vendor   = "Apple Inc."
    sys_product  = "MacBook5,1"
    sys_version  = "1.0"
    bios_version = "    MB51.88Z.007D.B03.0904271443"

I’m at a loss here.  If anyone has any hints, something else to try or 
a pointer to a good rundown on this, greatly appreciated.