As chomatic states, perlport might turn something up. A little more information might help, though. "Doesn't work" is fairly general -- for what value of "doesn't work"? Also, what version of perl -- and is it the same on both machines? The dbmclose looks vaguely suspect to me, as that construct is depreciated in all current perls.

Update: FYI, the following code works fine for me under ActivePerl 5.6:

use DB_File;
tie %add, "DB_File", "foo.db" or die "Can't open FILENAME: $!\n";
$add{time} = time;
untie %add;
[download]

Adding the dbmclose doesn't change it, either. Because you didn't use dbmopen to open the database, it isn't needed. Nor should it ever be, because tie has replaced it. ;>

 
perl -e 'print "I love $^X$\"$]!$/"#$&V"+@( NO CARRIER'