Question: I have been searching over the net for a specific solution on this problem in magento connect but I can't hardly find the right solution to solve it I have been constantly deleting files such as cache.cfg and connect.cfg as what other solutions have been stating but it would work temporarily then accessing it again would bring the problem back this also prevents me from installing new modules over the site, this is what I see:

Cannot unpack gzipped data in file contents: '/var/www/magento/downloader/../downloader/cache.cfg'

what do you think really causes this?

Answer: 
Try deleting the config.cfg file and check. Don't forget to take the backup of the same. 

Hope it works for you.
The proper file to delete in this case is cache.cfg. Of course You can delete connect.cfg as well. Both are generated at entering magento connect.