We really suggest you post your question to the bioperl mailing list - bioperl-l _at_ bioperl.org as that is where the bioperl developers hang out.

What version of Bioperl? What specific keywords did you use and db? Do you want to join your keywords together with an AND instead of space?

I can run things fine on the following query which gets barley ESTs. I am using bioperl-live code from CVS but I also tested it with the bioperl 1.4 release as well and it worked great.

&search('nucleotide','txid4512[orgn] AND gbdiv_est[PROP]');
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And I also made your loop actually do something

my $i;
while ( my $seq = $seqio->next_seq() ) {
        # do something with the data
    print $seq->display_id, "\n";
    last if $i++ > 5;
}
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