Linux tar.gz version (2.1.1) error?

after tar -xzvf jive_messenger_2_1_1.tar.gz all files are extrected, but i see this line at the end of operation:

tar: A lone zero block at 26929

hm… latest dauly build says the same, only block is at 26972, so maybe it’‘s not an error. I’'m not good in linux:)