problem in pdf report using fop lib

Greetings,

        I need to generate some report using XML+XSLT. I am using SAXON 
xslt processor and XSLT version 2.0.
        I am getting an out of memory error while generating the pdf 
report. Whereas the Excel report with the same contents works well.
        The report size is also not too big, less then 1MB. 
        Could anyone please help me out as to what could be the problem.
        Is there any other library apart from Apache FOP that I could use 
with SAXON to generate the PDF output.

Regards.
Neeraj,