After much testing I figured it out. I previously HAD solved the problem, but I found another one just now.
The first issue is this:
in admin.php look for the line "function getcfields"
Change the first few lines to this, with changes in bold:
function getcfields($list,$xtra=''){
global $ltable, $link;
if($xtra=='users') $terse = 1;
$cmd = "select field1,field2,field3,field4,field5,field6,field7,field8,field9,field10 from $ltable where listnum = '$list' limit 1";
$lrow = mysql_query($cmd,$link) or die('admin-30-'.mysql_error());
Now, that solves it partially, however there is STILL a problem -if- the second database access info is the SAME as the ListMail config.php info. In such cases PHP appears to apply the same "Resource ID #" to both MySQL connections and again we get the admin-30 error. I will have to do further testing to fix this.
Until then you may want to try setting up an additional user with access to the target database and using that user information for import.
Regards