The plugin pages shouldn't be recreated whenever the file changes. Instead the pages should connect to the ThunarxFileInfo's "changed" signal.
Committed with revision 19707. 2006-02-01 Benedikt Meurer <benny@xfce.org> * thunar/thunar-properties-dialog.c: Don't recreate plugin pages if the file changes, but instead let the plugins connect to the file's "changed" signal and update their user interface appropriately. Bug #1355.