Every once in a while IE11 suddenly forgets to automatically fill in my credentials to websites making it necessary to manually enter them - Well... Selecting them from the dropdown list where you'd enter the credentials would be more accurate.

Doesn't happen with every website - Eightforums for an example, which I haven't visited in QUITE a while, still had me active and ready to make this post while daily visited Websites like Deviantart.com occasionally require me to reactivate my Login.

As far as I can tell this happens on both the Desktop as well as on the Metro version and on all of my 3 PC's running W8.1

Any ideas what is causing this and how to prevent this from happening?

Thanks in Advance :)