We are running IE8 as a RemoteApp on Windows Server 2008 R2 Remote Desktop Services "Terminal Server". It has Reader X installed.
When opening linked PDF document, it shows the protected mode "fail" dialog.
If, instead, explorer.exe is launched as remote app, and ie8 is started from explorer,
opening PDF files in protected mode works.
This is regardless of settings, 32/64 bitness, whether iexplore is launched as remote app or
in full RDP session using "alternate shell:". If explorer is not parent of the process subtree,
protected mode doesn't work.
What might be the issue, and is there a workaround that does not involve starting explorer.exe?
This problem is fixed in the latest Reader X update 10.1.