If you feel you've found a bug in the Document Library Migration Tools, the problem can't be fixed until someone actually reports the problem to Microsoft product support and a support case is opened.
When you feel you have found a bug, call MS product support and ask for help. No need to feel intimidated. You will need to have credit card or support contract with Microsoft - however, it doesn't cost you anything when the problem is found to be a Microsoft bug.
Whenever the problem is found to be a bug in a supported product, your credit card or support contract will be credited for the problem. It won't end up costing you anything. The SharePoint Portal Server 2003 Document Library Migration Tools are a supported product.
The North American Microsoft support number for partners is: (888) 456-5570.