Index: lib/redmine/export/pdf.rb
===================================================================
--- lib/redmine/export/pdf.rb	(revision 11227)
+++ lib/redmine/export/pdf.rb	(working copy)
@@ -267,6 +267,8 @@
               format_date(value)
             elsif value.is_a?(Time)
               format_time(value)
+            elsif column.name == :spent_hours || column.name == :estimated_hours
+              value = (value.to_f != 0 ? ("%.2f" % value.to_f) : "")			  
             else
               value
             end