I can only post the solution I have used again. This takes perhaps 5 minutes in inexperienced hands and fixes the problem forever. You do not need to delete anything.
Essentially, it redirects any connections your computer tries to make to www.mevio.com to somewhere else; this causes itunes' attempt to update the podcast to silently fail, rather than bringing up the prompt. No need to hunt for the offending podcast, delete anything, or change the update settings. At various points it may prompt you to enter your password.
- Close itunes
- Open Finder, and select Go > Go to Folder
- Type /private/etc/hosts into the dialogue box and hit Go
- Copy the hosts file to the desktop
- Rename the original copy (in the etc folder) as hosts-original or something like that - as a backup in case you make a mistake
- Open the copy of hosts on the desktop with Textedit; it will look something like this:
##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting. Do not change this entry.
##
127.0.0.1 localhost
255.255.255.255 broadcasthost
::1 localhostfe80::1%lo0 localhost
You want to add a line after the line which reads "255.255.255.255 broadcasthost", redirecting any requests to www.mevio.com to another IP (I used 0.0.0.0). After editing, the file will look something like this:
##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting. Do not change this entry.
##
127.0.0.1 localhost
255.255.255.255 broadcasthost
0.0.0.0 www.mevio.com
::1 localhostfe80::1%lo0 localhost
Move the edited version back into the 'etc' folder (it will prompt for your password)
Voila! I hope this was sufficiently clear.