There is a fix for this issue in the DataAssist Download center page. In the known Issues section, look for the "DataAssist 2: Support Fix - Page redirects created with DataAssist 2.0.8 are not working correctly" Link to download the fix.
alternatively, you can find this line:
if (function_exists("rel2abs")) $WA_redirectURL = $WA_redirectURL?rel2abs($WA_redirectURL,dirname(__FILE__)):"";
and comment it out:
//if (function_exists("rel2abs")) $WA_redirectURL = $WA_redirectURL?rel2abs($WA_redirectURL,dirname(__FILE__)):"";