Do you mean browser caching? I tried THREE different browsers and in-private with all three and the gallery would never update. Not until I removed the plug-in and added back onto the page did it update.
Well…after trying different options to fix this, what worked was to delete the NextGen plug in from the page, update the page, add the plugin back onto the page and update.
Unnecessary extra steps (should just update), but it works. 🙁
