Wikimedia Bugzilla is closed!

I can upgrade from version 1.4.5 to 1.4.10.  But when I try to upgrade from either 1.4.5 or 1.4.10 
to a 1.5.* or 1.6.* release I fail with the following message.

Tag conditions not met. This should never happen and is a bug.
Backtrace:
GlobalFunctions.php line 451 calls wfbacktrace()
Sanitizer.php line 670 calls wfdebugdiebacktrace()
Sanitizer.php line 552 calls sanitizer::gettagattributecallback()
Parser.php line 655 calls sanitizer::fixtagattributes()
Parser.php line 784 calls parser::dotablestuff()
Parser.php line 193 calls parser::internalparse()
OutputPage.php line 254 calls parser::parse()
OutputPage.php line 245 calls outputpage::addwikitexttitle()
refreshLinks.inc line 89 calls outputpage::addwikitext()
refreshLinks.inc line 55 calls fixlinksfromarticle()
rebuildall.php line 34 calls refreshlinks()

MediaWiki (http://wikipedia.sf.net/): 1.4.5 
PHP (http://www.php.net/): 4.3.4 (apache2handler) 
MySQL (http://www.mysql.com/): 4.0.18-Max