While all browsers support Last-Modified and ETag headers properly, MSIE seems not, it wouldn't let you refresh a page generated by b2 0.6.1. And that sucks, I know.
Here is the fix: clickie!
(This fix will be included in the releases asap.)

b2 0.6.1 is out, waiting for you to download it!
What's new:

• TrackBack 1.1 (adds compatibility with newer MT versions' TrackBack).
• RSS 1.0 (b2rdf.php) and 2.0 (b2rss2.php) feeds. For those who upgrade, writing to b2rss.xml is still supported but you're encouraged to just use b2rss.php.
• b2 now generates Last-Modified and ETag headers based on your last post's date (very useful for aggregators).
• Improved paged presentation when using next_post() and related tags.
• Clearer PingBack excerpts
• Various bugfixes, as usual.

Also, w.bloggar 3 is out too!