Redmine

I'm struggling with an issue with a 3.0.4 install of redmine, where IE users have to enable "compatibility mode" in order to get any pages on the site to render properly. Without compatibility mode on, the pages are rendered as large font, plain text.

I could really use some help with this, having the users switch compat mode back and forth is not going to be an acceptable solution (there are other services on the same domain that break with compat on).

The server is ubuntu 14.04 LTS with standard apache/mysql. Ruby/Rails installed via rbenv.

From the info page:
Environment:
Redmine version 3.0.4.stable
Ruby version 2.2.2-p95 (2015-04-13) [x86_64-linux]
Rails version 4.2.3
Environment production
Database adapter Mysql2
SCM:
Subversion 1.8.8
Git 1.9.1
Filesystem
Redmine plugins:
no plugin installed