I've got also the same problem, I can't for the life of me, get the ENB DOF (Bokeh) working on my new computer. It used to work on my old one.
Other effects seems to work fine but not the DOF.
Things I've tried:
- Different Nvidia drivers
- Reinstall of Skyrim
- All mods disabled
- MSAA forced off
- bFloatingPointTarget=1
- Different ENB presets & ENB versions
- ForceFakeVideoCard=true (because it worked for some1 else in this thread)
- Regenerated Skyrim.ini and SkyrimPrefs.ini
- Uninstalled some extra applications such as overclocking utilities for my mobo in windows (since it runs in the background)
- Disabled Antivirus to ensure that it couldn't somehow cause the enb stop working like it should be
Nothing seems to help.

It's driving me nuts because noone else seems to have this issue.
Computer specs:
Intel i5 4670K @ 4.4GHz
Asrock Extreme6 Z87 motherboard
Nvidia GTX 760 2GB
16GB DDR3-1866
Samsung Pro 840 128GB SSD
120 Hz Monitor
Windows 7 64bit Professional
etc.