Open File Options and check for a script set to run when the file is opened. Clear that selection and this script will no longer run when the file is opened.
If that does't fix the problem, look for a script specified to run from an "OnLayoutEnter" or "OnRecordLoad" script trigger. Select layout mode on the layout you first see when the file opens (Check File Options to see what layout might be specified there.) and choose layout setup.. from the Layouts menu. Click the Script triggers tab and see what's there. You can disable the trigger by clearing its check box.