The problem seems to exist only on 2.4b2. It looks like the netui.dll included in the image is the standard one from MS instead of the Toradex modified one which adds the system try functionality (As MS removed complete Explorer functionality in CE8).
Not sure why this happened, it looks like during the build process netui.dll was not overwritten with our special version. Maybe some antivirus blocked access to the file… i will investigate more, but by rebuilding the issue seems not to be reproducible,
I will fix this in the next release and make sure that it does not happen again.
In the meantime you can patch this issue by adding the right netui.dll to the \Flashdisk\EarlyAutocopy\windows folder and enable the EarlyAutocopy feature.
For your convenience i added a .reg file you can just double click and the correct netui.dll here: