Syntax highlighting doesn't work for multi-line comments ( *.py and *.html)

Syntax highlighting is only displayed on the first line of a python multiline string or within the first element of commented-out html block.

The rest of the syntax highlighting works fine (keywords in python and html picked out) so gedit is definitely applying the correct style.

e.g. In a *.py file, the whole of the following multiline string should be highlighted in pink, but only the first line is highlighted.

""" This line has the correct syntax highlight colour
This line is not highlighted
"""

..and in a html file, only the first element ( the <!--ul> )is shown as commented:

<!--ul><li></li>
</ul-->

Version of gedit: 2.18.1
Kernel: 2.6.20-16-generic