OK, more search on the google once i find out it always start at layout 256,
results found on filemaker website:
Selecting a layout higher than 255 from the layout popup menu in the status area of FileMaker Pro for Windows results in being taken to the very last layout of the database. For example, in a database with 300 layouts, selecting layout number 260 from the layout menu would result in being taken to layout 300 in FileMaker Pro for Windows.
This issue is not encountered in FileMaker Pro for Macintosh. For Windows based databases that have more than 255 layouts, scripts can still target the correct layout. A script that uses the "Go To Layout" step will go to the specified layout, even if it is above 255.
FileMaker is aware of this issue with the FileMaker products listed
The last update on that is Mar 22, 2012
Is there a fix or any other way around this since then?