If you receive a Download Error when updating the TV Guide EPG, that may be due to a proxy server for your internet access. The wording of the error reported by EyeTV may be similar to the following:
"Download Failed. Unable to decompress the data received from the TV Guide server."
Some users may have a HTTP proxy server enabled. EyeTV's EPG downloading presently is incompatible with proxy servers. Proxy servers generally decompress the HTML when returning the data, and EyeTV expects compressed data.
We hope to fix this in a future release. Depending on the proxy server, you could add EyeTV to a list of applications that never get proxied data; or you could add the following domains to the list of bypassed hosts in the Network preferences.
For TV Guide: services.eyetv.com, epg.eyetv.com
The proxy settings can be found in System Preferences > Network > Advanced > Proxies.