about gmap

It has trooble me for several days
I added gmap module to gallery2.2.2. The map can be seen correctly but the point cannot be saved. Everytime when I click "save these coordinate" the error page appears:

===============================error page===========================
Authentication Failure

Your change cannot be completed due to a loss of session data. Please try again. If it still doesn't work, try logging out and logging back in.

Back to the Gallery
Error Detail -
Error (ERROR_REQUEST_FORGED)

* in modules/core/classes/GalleryController.class at line 239 (GalleryCoreApi::error)
* in main.php at line 224 (GalleryController::assertIsGenuineRequest)
* in main.php at line 94
* in modules/core/classes/GalleryEmbed.class at line 179
* in /home/baobaopa/public_html/shareourphoto/modules/gallery/gallery.module at line 215 (GalleryEmbed::handleRequest)
* in ??? at line 0
* in /home/baobaopa/public_html/shareourphoto/includes/menu.inc at line 418
* in /home/baobaopa/public_html/shareourphoto/index.php at line 15

=========================end of error page=====================

If you do a forum search (map authentication failure), this issue comes up several times. The short answer: use the SVN version.