Oh a past fan....
Yes - there is definately a problem with the first time install of guide data and its scanning (why should you need to scan at this stage at all is probably a good question too!).
And you guys are correct - start a scan, stop it, delete all the channels and then do the scan again - is the most reliable solution, in rare instances you may find the need to do it a couple of times - a real pain in the neck.
The next problem that occurs, is sometimes - purely at random - you can loose a channel or all the channels... No guide data to be found at all. this only occurs for digital tuner setups, and happens more times than enough pre RU2. Rollup 2 (RU2) was to address this, and failed miserably because of some last minute changes made for Eurpean users, and hence one of the reasons for the update to the update of RU2.
Morale of the story is to ensure you have all the updates installed (and dont be frightened of RU2 because you cant use Crunchie - you can!)
If it happens, the only solution is to go through the installation process of icetv setup / do the scan / map the channels again. Luckily it does not occur often - and appears to possibly be a timing issue, but I know its not a great help to you - but at least the bug is somewhat acknowledged....
If it happens to you more than once a month - hmmmm.... something may be seriously wrong with your setup though!