MacBook – Multiple kernel panics per day on MacBookPro4,1 2008 mostly in web surf mode

I've had freezing issues more and more frequently (now multiple per day) with my early 2008 Macbook Pro 4,1

I've pasted a recent kernel panic log beneath, and hope someone can point me in the right direction.

This problem was happening on OS X 10.6 recently, and I did a Rember test on the memory which looked "ok", as well as verified the hard drive in single user mode—also checked out "ok".

I've since done a clean install of 10.8 but the problem persists. Other stuff that may/may not be related: optical drive is dead, and the battery barely holds a charge any more :/ maybe 6 years is enough for this baby

 Machine-check capabilities 0x0000000000000806:
 family: 6 model: 23 stepping: 6 microcode: 1548
 Intel(R) Core(TM)2 Duo CPU     T9500  @ 2.60GHz
 6 error-reporting banks
 threshold-based error status present
Processor 0: machine-check status 0x0000000000000005:
 restart IP valid
 machine-check in progress
MCA error-reporting registers:
 IA32_MC0_STATUS(0x401): 0x1000000000000000 invalid
 IA32_MC1_STATUS(0x405): 0x0000000000000000 invalid
 IA32_MC2_STATUS(0x409): 0x0000000000000000 invalid
 IA32_MC3_STATUS(0x40d): 0x0020000000000000 invalid
 IA32_MC4_STATUS(0x411): 0x0000000000000011 invalid
 IA32_MC5_STATUS(0x415): 0xb200001806000e0f valid
  MCA error code:            0x0e0f
  Model specific error code: 0x0600
  Other information:         0x00000018
  Threshold-based status:    Undefined
  Status bits:
   Processor context corrupt
   Error enabled
   Uncorrected error
Processor 1: machine-check status 0x0000000000000004:
 machine-check in progress
MCA error-reporting registers:
 IA32_MC0_STATUS(0x401): 0x1000000000000000 invalid
 IA32_MC1_STATUS(0x405): 0x0000000000000000 invalid
 IA32_MC2_STATUS(0x409): 0x0000000000000000 invalid
 IA32_MC3_STATUS(0x40d): 0x0020000000000000 invalid
 IA32_MC4_STATUS(0x411): 0xf200000000060151 valid
  MCA error code:            0x0151
  Model specific error code: 0x0006
  Other information:         0x00000000
  Threshold-based status:    Undefined
  Status bits:
   Processor context corrupt
   Error enabled
   Uncorrected error
   Error overflow
 IA32_MC5_STATUS(0x415): 0xb200003008000e0f valid
  MCA error code:            0x0e0f
  Model specific error code: 0x0800
  Other information:         0x00000030
  Threshold-based status:    Undefined
  Status bits:
   Processor context corrupt
   Error enabled
   Uncorrected error
panic(cpu 1 caller 0xffffff8001cb8389): "Machine Check at 0x51ce37a4f09a70c0, registers:\n" "CR0: 0x0000000080010033, CR2: 0x000000005aae0000, CR3: 0x000000002b9bb000, CR4: 0x0000000000000660\n" "RAX: 0x3f63e0cb68ad5356, RBX: 0x0000002300000000, RCX: 0x9f7eb0c600000000, RDX: 0xbffb0ed0bffb0e58\n" "RSP: 0xf4692a1fbaab5046, RBP: 0xbffb0e1000000000, RSI: 0x0000002300000023, RDI: 0x000000000000000f\n" "R8:  0xbffb0eecbffb0ecc, R9:  0x0478021800000001, R10: 0x5aae0000bffb0e98, R11: 0x0021028600000000\n" "R12: 0x0000001b00000000, R13: 0x01ab378b00000000, R14: 0x00000000ffffff80, R15: 0x01cced7000000000\n" "RFL: 0x10b24c7051b04c20, RIP: 0x51ce37a4f09a70c0, CS:  0x000000000000b18d, SS:  0x000000000000a30e\n" "Error code: 0x1dfaf9b50de147ea\n"@/SourceCache/xnu/xnu-2050.7.9/osfmk/i386/trap_native.c:280
Backtrace (CPU 1), Frame : Return Address
0xffffff8074e25f20 : 0xffffff8001c1d5f6 
0xffffff8074e25f90 : 0xffffff8001cb8389 
0xffffff8074e26100 : 0xffffff8001cced7f 

BSD process name corresponding to current thread: Google Chrome He

Mac OS version:
12A269

Kernel version:
Darwin Kernel Version 12.0.0: Sun Jun 24 23:00:16 PDT 2012; root:xnu-2050.7.9~1/RELEASE_X86_64
Kernel UUID: 8D5F8EF3-9D12-384B-8070-EF2A49C45D24
Kernel slide:     0x0000000001a00000
Kernel text base: 0xffffff8001c00000
System model name: MacBookPro4,1 (Mac-F42C89C8)

System uptime in nanoseconds: 4887982849617
last loaded kext at 1927504231579: com.apple.filesystems.smbfs  1.8 (addr 0xffffff7f83d9d000, size 229376)
last unloaded kext at 176428418700: com.apple.driver.AppleFileSystemDriver  3.0.1 (addr 0xffffff7f83cb1000, size 8192)