Problems with Older Magazine Theme

I'm using a very old version of Magazine.

Recently, registrations stopped working. Nothing I've done has worked so I decided to replaced the BP 1.1.3 plugin I'm using. For some reason, this killed the site: everything under the header turned white for Magazine 1.1.9.

Currently I defaulted to 1.0.5 and all the content shows up - but some plugins don't work (is this is a theme issue or BP issue - why would plugins suddenly stop working with an identical BP install?). So: any idea why 1.1.9 isn't working?

I have the newest Magazine downloaded, but given all that's happened just replacing a plugin, I'm wary of having to replace everything. I'm currently using MU 2.9.2.

Thanks.

Site is: http://selfpublishingreview.com