I had faced the same "problem" before.
But it got solved when I unparked the domain and put it in as add-on domain instead (I did that because I had to add another domain)
Try adding-on the domain instead of parking it and see if it helps.
p.s. - Doing this will mean that some scripts might stop working as expected (and might require some amount of fixing by hand)
I'll suggest you do it only if you know what you are doing, and if the address visible in the addressbar is more important than the effort required.
But ofcourse if somebody else has a better idea...
It may be a server setting.
I used this fix for my localhost apache server :
Search for UseCanonicalName in Apache's configuration file, and replace On by Off.
Thanks for the helps