Hi Shakar. Don't worry about your English. I wouldn't have noticed if you hadn't mentioned it.
Which aircraft are you having problems with? Most people run into trouble with jets & helicopters. Try a few prop planes from the newest files in the CFS2 sections first. My Aliasing article might explain it.
http://www.simviation.com/lair/aliasing1.htmAlso read the installation tute posted in the Help section.
http://www.simviation.com/acinstall.htmIf this is no help give me an example & tell me the page it's posted on so I can check it out.