Outlook 2013 hangs with addons disabled but works fine in /safe. Confused.

I'm out of ideas. Here's the problem:

Every user is having an issue when inserting a hyperlink. In the hyperlink edit box, a user will select "Look in" and instead of a drop-down, Outlook stops responding for about 30 seconds to a few mins.

I tried running outlook /safe which causes the Look in drop-down to work as it should. I naturally thought it was a addon problem. I then disabled ALL addons in the options menu, but the problem persists.

I thought /safe simply disabled addons and some views. What else does it do that I am missing? I've searched but haven't come up with any solutions. TIA.

EDIT:

Thanks for all the tips!

Additional Info:

*Office 365 Hosted Exchange

*We utilize redirected folders

*Happens on computers with and without iTunes

EDIT2: I give up, clicking [this button](http://i.imgur.com/H66YY1d.jpg) works much faster.