The developer worked to fix a slew of issues as well as improve the overall stability of the browser. However, they also announced an ongoing known issue that affects the Windows XP version. It is a small glitch that consists in a red overlay on windows controls.
Other modifications include blacklisting force-compositing-mode on Windows Vista and repairing a crash in BookmarkEditorView. The full list of changes is available on the page of the revision log.
Mind that this is the beta build for the application and glitches are very likely to occur.