Your problem seems to be the same like sn1405 has in the thread 'Contacts screen'.
I have tried the same thing at my end(removed some fields from commoncontacts.xsl) and my 'CreateAnother' button takes me to the modified xsl. Its working fine. Let me know if you have changed any of the following:
1. PersonContactManager.xsl
2. Person_contact.xml ( finder set xml)
3. PersonContactManagementServlet.java
Before doing the above check, check whether the link on 'CreateAnother' button is something like this
http://localhost/GC3/glog.webserver.contact.PersonContactManagementServ let/1182919085953?a=b&new=y
Note: Like i have written earlier in the other thread, this CommonContacts.xsl is a common file used across different UI in GC3, so its not advisable to change this xsl
unless your requirement says that this change should reflect in all other UI.