Difficulty with 1080p

So, there is a whole sordid story here, but the long and the short of it is, I am, and always have had difficulty playing 1080p content on my HTPC. _ANY_ 1080p. I can play it, but there are severe dips in framerate when the bitrate goes up.

Specs:
20:35:44 T:1508 NOTICE: Starting XBMC (11.0 Git:20120321-14feb09), Platform: Windows 7, 64-bit (WoW) Service Pack 1 build 7601. Built on Mar 21 2012 (compiler 1600)
20:35:44 T:1508 NOTICE: AMD Phenom™ 9150e Quad-Core Processor
20:35:44 T:1508 NOTICE: Desktop Resolution: 1920x1080 32Bit at 59Hz
20:35:44 T:1508 NOTICE: Running with administrator rights
20:35:44 T:1508 NOTICE: Aero is disabled

I recently moved to Windows 7 after upgrading to a Quad-Core CPU did nothing to help, I moved to 4g of ram because of the upgrade. Windows itself runs fine, and if I use VLC or MPC, the videos play fine. Currently I am using mapped drives to take advantage of windows file caching. At this point, the videos are running _WORSE_ than they were in XP. In xp, the dips were less severe, and less frequent than they are in 7. I was under the impression that moving to 7 would allow the full use of the CPU in XBMC, but that is not the experience I am having. If I use 30% of the CPU in software mode,

I have tried all three video rendering modes, I have tried "windowed" mode, and the framerate limiting options. I am kind of out of options here, and could use some help trying to get this to work properly.

LOG:
http://pastebin.com/ERUd7ws1