Illustrator Data-Driven Graphics Error - XML linked file Variables wont work

Question

So I am trying to create a document with Data-Driven Graphics in Illustrator [Mac OSX 10.7 + Illustrator CS5].

Using the Variable Panels, I used the existing content to create a Data Set exported it and edited the xml file to create different Data Sets. It worked seamlessly when using only text-based variables however when trying to use linked files as variables (Images). Illustrator would not let me change Data Sets claiming "unknown" error. I've looked all over but can't seem to find an answer to this error. Anyone have a clue is the address to the linked file wrong?

Variable Definitions

    <variables>
        <variable  varName="Variable1" trait="textcontent" category="&ns_flows;"></variable>
        <variable  varName="Description" trait="textcontent" category="&ns_flows;"></variable>
        <variable  varName="QrCode" trait="fileref" category="&ns_vars;"></variable>
        <variable  varName="CoverImage" trait="fileref" category="&ns_vars;"></variable>
    </variables>

Data Sets

    <v:sampleDataSets  xmlns="&ns_custom;" xmlns:v="&ns_vars;">
    <v:sampleDataSet  dataSetName="DataSet1">
            <Variable1> <p>Other Reference</p></Variable1>
            <Description><p>Description Text Blurb</p>
            </Description>
            <QrCode>file:////File/Path/to/image1.eps</QrCode>
            <CoverImage>file:////File/Path/to/image1.eps</CoverImage>
    </v:sampleDataSet>
    <v:sampleDataSet  dataSetName="DataSet2">
            <Variable1> <p>METAL MIX SNAKE</p></Variable1>
            <Description><p>Description Text Blurb</p>
            </Description>
            <QrCode>file:////File/Path/to/image2.eps</QrCode>
            <CoverImage>file:////File/Path/to/image2.eps</CoverImage>
    </v:sampleDataSet>
    </v:sampleDataSets>

Answer 1

In illustrator CS5 there is a bug for linked files in variables. You receive a filter unkown error. It still work in CS4, CS3 & older versions. Perhaps it work again in CS6.

Answer 2

I've run into random XML errors in Adobe products (AI and InD) in the past. I don't do much of that anymore so I can't speak to CS5 in particular. In my experience, some unknown corruption seemed to creep into the file. In InD, export to .inx can solve it.

A total guess: I would try saving back to CS4 to see if that process dumps any culprits for you. Other than that, test your XML in a clean file and you may come to the sad conclusion that you have to build from scratch.