I'm having similar problems with strike effects too..
Also , I sometimes can not see the missiles or bullets at all..
My picture or display if you will, freezes momentarily and that suggests to me that there is a frame rate issue.
One weird thing that happens with me is when I am using (another company) (AIRHAULER) I can see the missiles launched from my aircraft and the strikes on the ground with smoke and displacement of earth along with explosion sounds with no freeze-up.
Some unexplained behaviour with my computer.. But I think Weapon for FSX (WFSX) needs alot of computer power to get what we are all craving for.
I really hope that the developers are working on a patch or update to fix all the bugs and what nots.
I support you guys.. Come on, lets get this add-on poppin'.