Hiya,
Did you initially start a career without OHII ?
For OHII to work, you have to either do the career start game, dock at kiel, exit, load mods, start new OHII career
Or, on mission option start page type in 'silentotto' and then start a career, then exit and then load mods
Or thirdly, this works but no idea if it effects anything later in the game
Goto sh5 folder (usually in your docs folder) , edit CareerHistory.cfg line to read HasCompletedTutorial=false to HasCompletedTutorial=true , this assumes you already have sh5 installed with the above .cfg in from previous gaming etc
Hope that makes sense
ps : can also be using 3d clouds if gpu isn't up to it, using shadows, too much AA and other graphics settings
C++ 2008 runtime (search here for offending one)
Corrupt OHII download (guy last week had exactly that)
pps : vdr the genius, check this link out
http://www.subsim.com/radioroom/showthread.php?t=210153