The author has marked this style as obsoleted by Greasemonkey - cleaner manage window.
This has been done better by DesertFox.




Makes GM's Manage User Scripts window not resize the columns when selecting a script.
good idea.. this was always an annoyance, still a little jerky though
This also works:
@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);#manage-window grid > columns > column:first-child {
min-width: 175px !important;
max-width: 175px !important;
}
.ad {
/* Your ad can be here instead. 10K unique visitors for $5/day. Mail me. */
}