$$a^3$$
$$a^2$$
$$a^2$$
$$A^b$$
in it.
All I see presented is a^2 (shown twice correctly).
When I reload the page I can see four images being loaded but the first and last are blank (not unassigned).
When I view the Resource source, I see
<table align="center" class="generalbox" border="0" cellpadding="20" cellspacing="0"><tr><td bgcolor="#FFFFFF" class="generalboxcontent"><p><a href="http://localhost/moodle/filter/tex/texdebug.php"><img border="0" title="a^3" alt="" src="http://localhost/moodle/filter/tex/pix.php/0e12d972c205ea4de06749a887ff1ffe.gif" /></a><br />It is possible (indeed probable) that the a^2 image was created with 1.4.3+.
<a target="popup" title="TeX" href="http://localhost/moodle/filter/tex/displaytex.php?a%5E2" onClick="return openpopup('/filter/tex/displaytex.php?a%5E2', 'popup', 'menubar=0,location=0,scrollbars,resizable,width=300,height=240', 0);"><img border="0" title="a^2" alt="" src="http://localhost/moodle/filter/tex/pix.php/ebc3d7bedc1f11e08895c3124001cbb5.gif" /></a><br />
<a target="popup" title="TeX" href="http://localhost/moodle/filter/tex/displaytex.php?a%5E2" onClick="return openpopup('/filter/tex/displaytex.php?a%5E2', 'popup', 'menubar=0,location=0,scrollbars,resizable,width=300,height=240', 0);"><img border="0" title="a^2" alt="" src="http://localhost/moodle/filter/tex/pix.php/ebc3d7bedc1f11e08895c3124001cbb5.gif" /></a><br />
<a href="http://localhost/moodle/filter/tex/texdebug.php"><img border="0" title="A^b" alt="" src="http://localhost/moodle/filter/tex/pix.php/6d949753733de31290fcce63a9bdb427.gif" /></a></p> </td></tr></table><center><p><font size="1">Last modified: Monday, 17 January 2005, 11:14 AM</font></p></center><!-- START OF FOOTER -->
Any ideas?