Comment 3 for bug 293696

To reproduce this bug I take the following steps:
0. I use Thunar to open files and associate file extensions. I have both file-roller and xarchiver installed.
1. Make sure *.deb files are opened with Gdebi by default (not with an archive manager).
2. Choose any file in Thunar and select 'Create Archive' from the menu.
3. The aforementioned dialog should appear. Choose any archive manager and click OK. After that you don't need to actually create an archive.
4. Try to open any *.deb file. You will see it is now associated with your previously chosen archive manager, as well as several other file types.

My guess is that thunar-archive-plugin has a pre-defined list of file types, which it associates every time the dialog is invoked. This behavior is wrong and should be changed.