See if this helps.
Yes, it doesn't like large pdf files
More hereWindows 8 build 7850, the first leaked Windows 8 build, may be old (it was compiled on September 22, 2010) as it's from Milestone 1, but not only does it contain new features such as the Portable Workspace but it also has a new Task Manager. Users on the My Digital Life forums have figured out how to turn it on and have taken a screenshot of how it looks (pictured below).
The new Task Manager is not completely functional in the aforementioned build (closing an application with the utility does not make it disappear from the list). Still, it's noticeably different. As you can see, there are three tabs: Programs, Startup, and Users (compared to Applications, Processes, Performance, and Networking in current versions of Windows). This will likely change, but it's still interesting to see what Microsoft is experimenting with.
It was a rhetorical question - LOL - thanks anyway.
Just so everyone's on the same page, the following features have been unlocked (not by me, lol) in 7850 AFAIK:
1) Modern reader (glcnd).
2) New Task manager (taskUI).
3) Webcam (webcam.exe).
4) Explorer ribbon.
Anyone know what happened to the pdf viewer (Modern Reader) in the dev preview version?
Doesn't seem to unlockable, or even present at all...
I like how the task manager looks. It looks pretty cool and it seems to work well with me.