vimperator plus 'disconnect' break site functionality

[castilma]

Vimperator:	3.16.0 (created: 2017/02/01 00:55:15)
Firefox:	Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:56.0) Gecko/20100101 Firefox/56.n0

Description:

Using the search functionality on http://suub.uni-bremen.de/ with 'vimperator' and 'disconnect' results in a blank page. I need to whitelist google with disconnect on that site to get to the results page. Disabling vimperator or disconnect or both or whitelisting in disconnect makes it work again.

Expected behavior:

After a short while on the blank page one should be redirected to the results page.

Steps to reproduce:

install disconnect and vimperator and try to search for a book. (the searchbar is the big one in the middle)

the bug

I dont know where the actual bug(s) is(are). what is strange is that disconnect seems to block the request to google only when vimperator is enabled.
if there is a bug in vimperator, it would be that it influences other plugins behaviour. any idea how vimperator might influence other plugins behaviour?