I have tried latest stable version on Ubuntu Lucid x64 (PHP 5.3) intall via Pear was perfect. EXCEL5, CSV and HTML works perfect but PDF give me table borders thick ( 4 px at least).
At the beggining it looks for fonts at /usr/share/php5/PHPExcel/PHPExcel/PDF/fonts Instead of /usr/share/php/data/PHPExcel/PHPExcel/... I copied directory fonts to the another one and works
I tried to paste over PDF dir files the latest version of tcpdf without sucess, in spite of it is suposed to work.
Now I get table borders thick and table header (first row) with different font style and words beign cutted.