test case for issue #1576 added

git-svn-id: svn://svn.code.sf.net/p/htmlunit/code/trunk@9131 5f5364db-9458-4db8-a492-e30667be6df6
verified with real ie8

git-svn-id: svn://svn.code.sf.net/p/htmlunit/code/trunk@9132 5f5364db-9458-4db8-a492-e30667be6df6