[R-SIG-Mac] .mpkg not recognized

[Martin Henry H. Stevens]

Hi Folks,
I can't install any R binaries any more, and have always done so in  
the past. The problem seems to be that my Mac no longer  
recognizes .mpkg i.e. doesn't know how to open it. I cannot find  
anything called Apple Installer on my machine (if I am supposed to  
have/see that...)?

My machine details follow. Any and all thoughts are appreciated.

Thanks,
Hank Stevens

Hardware Overview:

   Machine Name:	Power Mac G5
   Machine Model:	PowerMac7,2
   CPU Type:	PowerPC 970  (2.2)
   Number Of CPUs:	2
   CPU Speed:	2 GHz
   L2 Cache (per CPU):	512 KB
   Memory:	8 GB
   Bus Speed:	1 GHz
   Boot ROM Version:	5.0.7f0
   Serial Number:	XB3472Q1NVS

System Software Overview:

   System Version:	Mac OS X 10.4.6 (8I127)
   Kernel Version:	Darwin 8.6.0
   Boot Volume:	OfficeHD
   Computer Name:	MHHS (3)
   User Name:	Martin Henry H. Stevens (Hank)

Dr. Martin Henry H. Stevens, Assistant Professor
338 Pearson Hall
Botany Department
Miami University
Oxford, OH 45056

Office: (513) 529-4206
Lab: (513) 529-4262
FAX: (513) 529-4243
http://www.cas.muohio.edu/~stevenmh/
http://www.muohio.edu/ecology/
http://www.muohio.edu/botany/
"E Pluribus Unum"