Troubleshooting

Warning: You need to use EyeTV internal tuner for this to work; not s-video or composite (RCA) cables to listen to TV. i.e. EyeTV must be able to change channels by itself for EEP to work. This is a limitation in EyeTV.

First, you need to disable the cache to make sure you're not seeing cached data.
In TextEdit, open /Library/WebServer/Documents/eyetv-epg-proxy/dataservice.asmx/config.inc.php, and change the cache to 0 days:
$config['cacheDays'] = 0;

To try to find what the problem might be if you can't get EPG data in EyeTV, here's a couple of commands you can try in Terminal.app and the expected results.

The commands you need to enter are in bold. You should use copy/paste the commands in Terminal.app to make sure you don't make a typo.
The expected result are shown just below the commands.

1.
PowerMacG5:/ gb$ curl http://data.titantv.com/dataservice.asmx/RegisterUserZip?Zip=check
<?xml version="1.0" encoding="utf-8"?>
<ProviderCollection xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.titantv.com/services/dataservice">
<ErrorCode>0</ErrorCode>
<ErrorDescription>OK</ErrorDescription>
<Provider>
<ProviderId>S_10001</ProviderId>
<ServiceType>satellite</ServiceType>
<Description>Use 'type' => 'satellite' in config.inc.php</Description>
<City/>
</Provider>
<Provider>
<ProviderId>A_10002</ProviderId>
<ServiceType>cable</ServiceType>
<Description>Use 'type' => 'cable' in config.inc.php</Description>
<City/>
</Provider>
<Provider>
<ProviderId>D_10003</ProviderId>
<ServiceType>digital_cable</ServiceType>
<Description>Use 'type' => 'digital_cable' in config.inc.php</Description>
<City/>
</Provider>
<Provider>
<ProviderId>H_10004</ProviderId>
<ServiceType>analog</ServiceType>
<Description>Use 'type' => 'analog' in config.inc.php</Description>
<City/>
</Provider>
<Provider>
<ProviderId>G_10005</ProviderId>
<ServiceType>digital</ServiceType>
<Description>Use 'type' => 'digital' in config.inc.php</Description>
<City/>
</Provider>
</ProviderCollection>
PowerMacG5:/ gb$

2.
PowerMacG5:/ gb$ curl http://data.titantv.com/dataservice.asmx/RegisterUserZip?Zip=12345
<?xml version="1.0" encoding="utf-8"?>

<ProviderCollection xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.titantv.com/services/dataservice">
<ErrorCode>0</ErrorCode>
<ErrorDescription>OK</ErrorDescription>
<Provider>
<ProviderId>A_00001</ProviderId>
<ServiceType>cable</ServiceType>
<Description>your_provider_name_here</Description>
<City>your_city_here</City>
</Provider>
</ProviderCollection>
PowerMacG5:/ gb$

3. This is what a correctly configured Zap2It account will show. Note: Those are my channels - your Zap2It configuration defines what will show here.
PowerMacG5:/ gb$ curl http://data.titantv.com/dataservice.asmx/RequestLineupData?ProviderId=A_00001
<?xml version="1.0" encoding="utf-8"?>
<StationCollection xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.titantv.com/services/dataservice">
<ErrorCode>0</ErrorCode>
<ErrorDescription>OK</ErrorDescription>
<StationCount>49</StationCount>
<UsingCachedData></UsingCachedData>
<Stations>
<Station>
<station_id>21506</station_id>
<call_sign>Canal Club TV Achats</call_sign>
<rf_channel>10</rf_channel>
</Station>
<Station>
<station_id>21505</station_id>
<call_sign>Tele-Annonces</call_sign>
<rf_channel>12</rf_channel>
</Station>
<Station>
<station_id>17195</station_id>
<call_sign>Television Northern Canada APTN</call_sign>
<rf_channel>58</rf_channel>
</Station>
[...]
</Stations>
</StationCollection>
PowerMacG5:/ gb$

If this command takes more than 2 minutes to complete, or if it ends with the following response
curl: (52) Empty reply from server, it means your machine is too slow to process the XML data from Zap2It. EyeTV will give you an error because it takes too long.
Try to change the 'cacheDays' in your config.inc.php to 2m then repeat the above test a couple of times.
You can also try the suggestions found in this forum thread to fix this.

4. Note: This is an example of what not configuring config.inc.php with your Zap2It username and password might do; or if you have a wrong username or password for Zap2It.
PowerMacG5:/ gb$ curl http://data.titantv.com/dataservice.asmx/RequestLineupData?ProviderId=A_00001
<?xml version="1.0" encoding="utf-8"?>
<StationCollection xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.titantv.com/services/dataservice">
<ErrorCode>0</ErrorCode>
<ErrorDescription>OK</ErrorDescription>
PowerMacG5:/ gb$

To see the Apache error_log, and the actual error, do this:

PowerMacG5:/ gb$ tail /var/log/httpd/error_log
[...]
[Tue Sep 26 19:35:46 2006] [error] PHP Fatal error: Uncaught SoapFault exception: [HTTP] Unauthorized Request in /Library/WebServer/Documents/eyetv-epg-proxy/dataservice.asmx/functions.inc.php:266\nStack trace:\n#0 [internal function]: SoapClient->__doRequest('<?xml version="...', 'http://datadire...', 'urn:TMSWebServi...', 1, 0)\n#1 [internal function]: SoapClient->__call('download', Array)\n#2 /Library/WebServer/Documents/eyetv-epg-proxy/dataservice.asmx/functions.inc.php(266): SoapClient->download('1970-01-01T00:0...', '2006-10-04T00:0...')\n#3 /Library/WebServer/Documents/eyetv-epg-proxy/dataservice.asmx/RequestLineupData.php(13): getEPGData('A_00001')\n#4 /Library/WebServer/Documents/eyetv-epg-proxy/dataservice.asmx/RequestLineupData(1): include('/Library/WebSer...')\n#5 {main}\n thrown in /Library/WebServer/Documents/eyetv-epg-proxy/dataservice.asmx/functions.inc.php on line 266
PowerMacG5:/ gb$

If you ask for help in the support forum, please do all those tests, and indicate which of those tests failed, and what was the result when you entered the command for the failed test.