by Guillermo Madero S..
Hi Gwen,
The database should reference resources like files, images and such, but, unless they were using some external authentication system you shouldn't have any problems logging in.
As what you are doing is only to migrate their courses to a newer Moodle version, I skipped the process to change the Moodle URL (by using the replace.php script); however, if you need to update the address referenced in the database, then add this step.
Some time ago a few tools were developed, but as you already have found out, none are really that useful. The best course of action is by upgrading (definitely more work but one gets the best results).
If they won't have their severs upgraded to support Moodle 2, why do they need to migrate their data?