Yes, that's because of the URL that's being generated. It contains an & which should be escaped as &. You should be able to fix it by changing Calendar.php. Go to the buildFilterString function and change "&$key=$value"; to "&$key=$value";
@UncleCheese: It's probably a good idea to change this in your repository too. Generally you should always use & instead of & (when generating html or xml source)
No, the & wont be passed to the URL. & is perfectly valid (X)HTML and will always be rendered as &,even for URLs (eg. when you open the URL). You should use & in URLs. Just try it.
You put the $MonthNavigator feature back in, the only question I have about it is, is there a way to put the year after the month, as people will see april in the middle and then click say January above it.. then it gets confusing which year your in .... is there a simple way to tag on a 2 digit year afterwards?
I upgraded the module to the latest revision and see it has the dataobject manager method for adding dates etc, the only problem is if you try to add a repeating event it will just come up saying "To repeat an event, you must specify a date first." even though I have added in a date. or even on old events I had it wont let me edit the repeat event. The repeat event icon has no tick yet it shows the repeating date