Hi, 
  
Also trying to install ML on my Dell Inspiron 15R SE (core i5 3230m, 6gb RAM, 750Gb HDD, with ATI 7730M). I made a myHack USB installer using 10.8.4 and added Install bootpack for the Inspiron 7720, as this almost is the same laptop having a 17 inch screen, however the bootpack is for a i7 CPU. 
  
The installer freezes with the message (also seen on this forum): 
  
IOAPIC:version 0X20 vector 64:87 
  
What can be the cause of this? 
I tried boot options like PCIRootUID=0/1 and GraphicsEnabler=No didn't help. 
Should I use 10.8.0 as a base (how do I get it, having 10.8.4 installed on my iMac). 
Can the i5 b the problem having a bootpack for the i7 (7720)? 
  
Any help is appreciated....