Plugin affecting column width in posts page in wp-admin

I’ve traced a column width issue back to this plugin. When it is activated, the post title column in WordPress is reduced to a single character wide, so that it displays like:

P
o
s
t

T
i
t
l
e

This stops happening when the plugin is deactivated. I’d prefer to be able to keep using the plugin, however. Is this a known issue? Any fixes on the horizon?