The current version, Greenshot 0.8.0-0627, fixes some bugs and/or annoyances of the previous version. This includes a few errors that occurred under special circumstances. The most obvious changes in general are that new editor windows now open in the same position where previous editor windows have been closed, highlight and obfuscator elements no longer re-use the last used values (e.g. for line thickness and color) from other elements (e.g. rectangle) and that larger font sizes are allowed in the editor (has been limited to 24px before).
We recommend updating to the current version of Greenshot.