reportlab error

I have just installed openerp 5.0.7 on Centos 5.4 and python 2.4.and I am unable to print any reports (invoices etc...)

Traceback (most recent call last):
  File "/usr/lib/python2.4/site-packages/openerp-server/service/web_services.py", line 682, in go
    (result, format) = obj.create(cr, uid, ids, datas, context)
  File "/usr/lib/python2.4/site-packages/openerp-server/report/report_sxw.py", line 364, in create
    fnct_ret = fnct(cr, uid, ids, data, report_xml, context)
  File "/usr/lib/python2.4/site-packages/openerp-server/report/report_sxw.py", line 395, in create_source_pdf
    result = self.create_single_pdf(cr, uid, [obj.id], data, report_xml, context)
  File "/usr/lib/python2.4/site-packages/openerp-server/report/report_sxw.py", line 447, in create_single_pdf
    pdf = create_doc(etree.tostring(processed_rml),rml_parser.localcontext,logo,title.encode('utf8'))
  File "/usr/lib/python2.4/site-packages/openerp-server/report/interface.py", line 183, in create_pdf
    obj.render()
  File "/usr/lib/python2.4/site-packages/openerp-server/report/render/render.py", line 50, in render
    result = self._render()
  File "/usr/lib/python2.4/site-packages/openerp-server/report/render/rml.py", line 41, in _render
    return rml2pdf.parseNode(self.rml, self.localcontext, images=self.bin_datas, path=self.path,title=self.title)
  File "/usr/lib/python2.4/site-packages/openerp-server/report/render/rml2pdf/trml2pdf.py", line 781, in parseNode
    r.render(fp)
  File "/usr/lib/python2.4/site-packages/openerp-server/report/render/rml2pdf/trml2pdf.py", line 195, in render
    pt_obj.render(el)
  File "/usr/lib/python2.4/site-packages/openerp-server/report/render/rml2pdf/trml2pdf.py", line 771, in render
    fis += r.render(node_story)
  File "/usr/lib/python2.4/site-packages/openerp-server/report/render/rml2pdf/trml2pdf.py", line 700, in render
    return process_story(node_story)
  File "/usr/lib/python2.4/site-packages/openerp-server/report/render/rml2pdf/trml2pdf.py", line 693, in process_story
    flow = self._flowable(node)
  File "/usr/lib/python2.4/site-packages/openerp-server/report/render/rml2pdf/trml2pdf.py", line 565, in _flowable
    result.append(platypus.Paragraph(i, style, **(utils.attr_get(node, [], {'bulletText':'str'}))))
  File "/usr/lib/python2.4/site-packages/reportlab/platypus/paragraph.py", line 378, in __init__
    self._setup(text, style, bulletText, frags, cleanBlockQuotedText)
  File "/usr/lib/python2.4/site-packages/reportlab/platypus/paragraph.py", line 403, in _setup
    raise "xml parser error (%s) in paragraph beginning\n'%s'"\
TypeError: exceptions must be classes, instances, or strings (deprecated), not unicode

Any help would be appreciated

Thanks
Yvan