Loses all settings

Testing this plugin on a fresh WordPress install:
– everything untouched, default theme
– WP_DEBUG turned on in wp-config.php

PHP Notices after saving the settings:

Notice: Undefined index: twitget_show_powered in /xxx/twitget.php on line 365
Notice: Undefined index: twitget_use_custom in /xxx/twitget.php on line 370
Notice: Undefined index: twitget_before_tweets_html in /xxx/twitget.php on line 378
Notice: Undefined index: twitget_tweet_middle_html in /xxx/twitget.php on line 379
Notice: Undefined index: twitget_tweet_end_html in /xxx/twitget.php on line 380
Notice: Undefined index: twitget_after_tweets_html in /xxx/twitget.php on line 381
Notice: Undefined index: twitget_after_image_html in /xxx/twitget.php on line 382
Notice: Undefined index: twitget_before_profile_html in /xxx/twitget.php on line 383

Notice: Undefined index: show_relative_time in /xxx/twitget.php on line 545

Notice: Undefined index: title in /xxx/twitget.php on line 640 (on the Widgets admin page)

PHP notices are usually nothing to worry about, and the widget works at first. But when I then return to the settings page, all checkboxes are ticked, and ALL fields are populated with the same random, single character. Usually a or A, sometimes an unsupported character.

And this breaks the widget, of course:
Fatal error: Cannot use string offset as an array in /var/sites/t/twitget.antfarm.at/public_html/wp-content/plugins/twitget/twitget.php on line 208

I’ve deleted and re-installed the plugin a few times, but the behaviour remains the same: it happens every time, after I add the widget to a sidebar.

As bugs go, this is huge – I’ve never seen a plugin drop its settings like this. I hope you can find the problem.

http://wordpress.org/extend/plugins/twitget/