I have a production environment of Salesforce.com with huge data (more than 15,000 records) .. I bought Developer Pro Sandbox and created it. Now, I want to move my data to this Sandbox as it to do some tests on it. I exported All records of each object from production salesforce using Data Loader application. But when I import these files to Sandbox the IDs changed and the relations (lookups fields) got errors.
How can I solve this problem?