When I installed it on setting up a Calling Card I deleted the Access Code in the Dial Int Access Code option and after that got repeated Unexpected Error crashes. I deleted CCdialer and reinstalled but it still crashed.
Then I saw Krisna's message about the text files in \Application Data\CCDialer\ folder on your phone. I deleted all these and it worked perfectly after that.
In writing this I went into the set up Calling Card option again and used Ok to close it without any data in it. Crashes again. Deleted the .txt files and it all worked again. Went into Calling Cards again and this time used Cancel from the Menu options to get out and there was no problem.
I guess sometimes you have to be stupid to learn that the programmer knows best.
Many thanks Krishna for all your hard work.