Trailing slashes, some Views arguments break

With the latest release, I'm seeing trailing slashes no longer working - so /my/site/path/ breaks where /my/site/path works.

Also, some Views functionality breaking - a View without a specified argument in its path (ie: /calendar instead of /calendar/%) stops taking arguments. So what used to work as /calendar (using a default argument settings to produce the current month) works, but /calendar/2011-01 doesn't. A path argument has to be explicitly set in the View path, except that breaks the default argument functionality (so /calendar doesn't work anymore).