Various Problems internet explorer

Various Problems internet explorer

Hello, I hope someone can help answer a few riddles:

1: When logging into my application via Federated ID from Google Apps on internet explorer  you are asked for a domain login. Yet when using Chrome or Safari for example this doesn't happen.

2: If you open a pivot report in Internet Explorer I receive a warning about there being secure and non-secure items on the page, this again doesn't happen with any other browsers apart from Internet Explorer

3: Does anyone know what security features should and shouldn't be turned off and on in internet explorer.

Hope someone can help, thanks in advance

Rick