Please describe the problem:
txt2tags files (http://txt2tags.sourceforge.net/) are incorrectly determined by
GNOME to be postscript files and this complicates their editing as GNOME tries
to open them w/ the postscript viewer and not gedit (or another text editor).

Steps to reproduce:
Part 1:
1. Download example txt2tags file #1 w/ .txt extension
2. Notice it is seen as a plaintext file
3. Double-click said file
Part 2:
5. Download the other example file w/ a .t2t extension (t2t -> txt2tags)
6. The file is immediately given a postscript icon.
7. Double-click said file


Actual results:
Part 1: A dialog box pops up complaining that the file is a postscript file w/
the wrong extension.
Part 2: The GGV postscript viewer is opened and complains that the file is not a
valid postscript file.

Expected results:
Gedit or the default text editor app should be opened.

Does this happen every time?
Yes

Other information: