Folks,
After logging a ticket with RIM & trying many of the solutions on web forums and BB KB including a secure wipe, I seem to have found a fix for this issue on my own. It works for me. I changed the DNS Settings on my Playbook wifi profile to the OpenDNS Primary & Secondary IP. After this, when i tried installing an App on Appworld, it installed perfectly fine! So presume it was an issue with my Broadband service providers DNS Server.
I get an error while installing "protect the cheese" -- "install error: [0008]". Had the same issue while installing N.O.V.A 2 HD, but after doing a security wipe a day back, that problem got fixed. Any fix for this error?