no sound

I have no sound on flashplayer content in OPera or Chrome.  this is a persistant problem.  I do have sound on AOL but with a download (18.0.0.209) that has 17.6 mb.  I keep getting messages saying I must upgrade but I have 18.0.0.209 at 18.3 mb installed as well. 

I have tried all the easy stuff.

Dan you help