创建PDF文件时,HTML左箭头(“<”)不起作用

I have a problem with the FPDF class (very useful imho) which I'm using in my web page. I have a HTML table with some values, also with the "arrows" chars which in fact are causing the problem, but, especially with the left one ("<"). When I try to create my PDF file it works until it finds that character, and it shows nothing after that point. All i've tried until now is this:

str_replace("<","&#60;");

or

str_replace("<","&lt;");

but nothing is working so far. Does anyone know how to make this working? Seems like the PDF recognize it as an opening HTML tag and I don't know how to show that char