problem with addon domain

hi
my new addon domain is successfully set up and working as :
http://www.myNewDomain.com/

but i can’t find a way to make the internal links work appropriately.
for example ‘contact’ link works this way :

http://myNewDomain.myMainDomain.com/contact

but not this way :

http://www.myNewDomain.com/contact

I want it to act like the above line

I changed wordpress “siteurl” and “home” in wp_options field of database but no solution to make that work
help please.