Last night I upgraded to version 0.9.2; today an attempt to post gave me the error "Tag a may not have attribute HREF."
It turns out that b2evo was choking because the A HREF tag was capitalized. Since capitalization shouldn't make any difference in HTML code, this problem had me baffled for a while, and represents a frustrating bug.
Hope this is helpful.
xhtml says tags are lower case, and b2evolution says it is xhtml compliant. Thus tags gotta be lower case. Sure - upper case tags work, but it's not 'official' that way.