Hi.. I'm getting this same error in my DTD when I have an Attribute value = "11" .. It's type ID.. and I am pretty sure taht you can start an attribute value with a number.. here is my DTD Code..
<!DOCTYPE catalog [
<!ELEMENT catalog (cat+)>
<!ELEMENT cat (product,category,options)>
<!ATTLIST cat id ID #IMPLIED "">
<!ELEMENT product (productheader,producttitle,img+,product_description,price)>
<!ELEMENT productheader (#PCDATA)>
<!ELEMENT producttitle (#PCDATA)>
<!ELEMENT img EMPTY>
<!ATTLIST img src CDATA #REQUIRED>
<!ELEMENT product_description (#PCDATA)>
<!ELEMENT price (#PCDATA)>
<!ELEMENT category (name,img+)>
<!ELEMENT name (#PCDATA)>
<!ELEMENT img2 EMPTY>
<!ATTLIST img2 src CDATA #REQUIRED>
<!ELEMENT options EMPTY>
Any ideas??? Thanks.. Joss