create sharepoint site instead of subsite

Question

we have a strange problem while creating a new publishing site withing sharepoint 2007. for some reason if the user has Full Control than when he tries to create a new publishing subsite Via site action=>Create site then it create a sharepoint site instead of subsite. and when the user has site collection admin permission then he is able to create a normal subsite like you can see in the picture testmonday. is this a problem to do with the way they created the Site collection ? the problem is that we can not give all user SC Admin role.