I just upgraded a blog of mine to 2.7.1. After the upgrade, the Settings page for Twitter Tools now comes up empty, just a blank page. I've deactivated and reactivated the plugin. I've deactivated the plugin, deleted it from the plugins folder, loaded a backup copy, and re-activated the plugin. I've even bounced Apache on the server. Nothing has worked so far to bring the Settings page back.
I've checked my ID and I'm an administrator, too, so that's not it. It looks like the php is breaking somewhere as I never get a footer in the source code, it just ends after the contextual help accordion menu.
I've got the exact same version of the plugin running on a sandbox domain with the same theme and the same copy of the WordPress core, and it's having no problems with Twitter Tools. All of my other plugins are working and didn't experience any issues with the upgrade, in the sense that all Settings pages are available in the admin area.
Any ideas at all? This is just very weird...never seen this kind of behavior before.