I'm currently on OMNI Rom (Nightly) version 20140326 on my Int Galaxy S2, having this issue of USB Host driver missing.
I don't get a popup when I connect to any USB devices. I'm able to connect to USB flash drive, but unable to connect to my DSLR camera.
I dont have this issue on my Galaxy S i9000 phone which is flashed with 20140314 nightly. When I try to go to Settings>Storage>USB Computer connection, to change the settings, it doesn't allow me to go in
Previously I was on CM10 & had the same issue. I'm attaching the screenshot from the app, 'USB Host Controller' & from Phone status.
I checked with 'DSLR dashboard' app developer & this rom works fine for him. Appreciate your help to have this resolved.