LR 4.4.1 crashing on iMac osx 10.8.5 when using exposure and shadows sliders. Will not restart with out resetting surge protector. Worked perfectly for 1.5 years with upgrades to 4.4

Question

Hello,
       Thanks for any help you may have. LR 4.4 worked perfectly on iMac 27' OSX 10.8.5 for 1.5 years until October this year when shut downs began when making adjustments on primarily exposure and shadow sliders. Unit would not restart unless rebooting surge protector(s) after 10-15 minute wait. Apple replaced main board and cleared disc. Back-up and LR 4 reloaded and updated to 4.4.1. New surge protection or direct into receptacle makes no difference and shutdown happens immediately upon slider movement. Any suggestions or self checks an old guy can possibly do? It is Educator/student version.

Answer 1

Hello and thanks for the reply.
The entire computer shuts down and will not restart without a reset of the new (and previous) surge protector or if plugged directly to the wall receptacle anywhere from 30 minute to overnight reset before on button restart will work. Other than slider adjustments on LR, it has only shut down one other time when loading photos via USB 3.0 cable to LR. All images from camera are in RAW. Apple tried to replicate this earlier this week with LR but could not read anything other than an increased usage on one of the diagnostic meters when the sliders were moved quickly from side to side.
Other computer functions are normal and rarely used except for e-mail, web search, and 90% LR. Plenty of memory in reserve.
Considering two upgrades (1) LR 5 to get new camera profiles (Pentax K-3)
                                                  (2)Yosemite OSX if it would help the LR4.4 or LR5 actually behave
Hope this helps illustrate the dilemma and thanks for your support.