Problems logging in
I get an error "The username or password you entered is incorrect"
Your login attempt is going directly to Google instead of passing through JYU login. Clear cookies and cache from your web browser. Instructions can be found for example here.
I have to login twice, I get an error every first time
Your bookmark is pointing to a wrong address. When you create a bookmark, please check that the address is http://isamail.jyu.fi - if the address if https://login.jyu.fi/idp/Authn/UserPassword, you will need to modify the bookmark by right clicking and selection properties (or similar). Modify it to point directly to http://isamail.jyu.fi