I don't use it myself, have you tried contacting Richard Carlton Consulting for support?
One thing you could do is open up your script debugger in filemaker pro advanced to see if there's any trigger script firing when you press new record. That could help track down potential issues. The other obvious thing to check would be any "lookup" auto-enter fields in that table.
I think you'll have to be much more specific, including a description of which version you are using.
I have version 4.6.6 and briefly tried doing using the "New Record" button while in the Accounts detail view and did not get the result you described.