TOC fail to display entries

Hi,

I'm facing a problem with the '<' character in a paragraph when my script
tries to generate a TOC. For instance, in a set of entries in the TOC that
includes a phrase like "Amount of mercurium < 20 g per unit" my TOC would
look like:

Substancies analyzed per unit .............................. 10 

Amount of mercurium                                                 

Next topic of the document .................................. 19

In the document pages the phrase is shown complete with no problem at all. I
escaped the character using &lt; but as I said it worked every where else
but in the TOC.

I'm using reportlab platypus 2.7 and python 2 .6. 

Thanks for any help on that.

Regards 

Marcus Silva