hangs after login for some users

I'm a new employye at my company (but not new to tech support), and I've never worked with Sugar before. I know I don't have access to Sugar or the server running it, and after a day and a half of emailing I've managed to figure out that:
1) No one on my team knows anything about Sugar.
2) The non-technical person who knows the 2 people who do know Sugar and have access to the server will not share those names.
3) I have to definitively prove that these 2 must be contacted for support (apparently they do not work for my company) before this non-technical manager will contact them.
4) I will likely never have access to log in to Sugar let along the rights to work with files on the server...which is fu..awesome since all the Sugar trouble tickets are getting routed to me. 

So, my first request is, where is some good documentation?

My next question is why would 10 people be able to log in just fine while 2 other users (who could log in fine yesterday) experience incredibly slow logins? 10 people at one site enter their credentials at the login page and are promptly take to their Sugar accounts. 2 users enter their credentials and get to sit and watch the loading circle just spin and spin for more than 30 minutes but less than 45. Once they do get logged in, fields in drop down boxes are missing options, and things can't be saved. They are using Windows 8.1, and experience the issue with both IE and Chrome. I did clear their browser cache (files, passwords, forms, everything to  the beginning of time). I also added the tld to their trusted sites list (eg: https://*.thissite.com). None of that helped. I pinged the URL, and the average response was ~38ms so I don't think this is a networking error. Any ideas? Anything I should try?

Gotta love being handed stuff to support without any tools to support it.