Is this a problem with recent versions of httrack?
I found this thread from someone who seemed to be having the same issue, with
httrack 3.42. One of the responder said to stick to 3.33, as more recent
versions have problems with this.

Is that the solution? 

I have to say, I am a bit concerned about moving back to 3.33, as I have
implemented a lot of features around 3.45, and it seems a lot of things have
changed since then in the format of the cache and log files.