> Web Address:
> <http://oldweb.cs.cf.ac.uk/fun/welsh/>*.*

This last one isn't correct, actually - 
<http://oldweb.cs.cf.ac.uk/fun/welsh/>*.* looks like a filter 
(scan rule), but the correct syntax is:

+oldweb.cs.cf.ac.uk/fun/welsh/*.*

(Note the leading "+" which stands for "accept these files")

> Set Options-Scan Rules:
> +*.css +*.js -ad.doubleclick.net/*
> +*.zip +*.tar +*.tgz +*.gz +*.rar +*.z +*.exe
> +*.gif +*.jpg +*.png +*.tif +*.bmp
> +http://oldweb.cs.cf.ac.uk/fun/welsh/*

Okay, the scan rule is already here (note that 
+oldweb.cs.cf.ac.uk/fun/welsh/* is also correct)

> 11:36:36 Error:  "Interrupted transfer" (-4) after 2 
> retries at link 
> oldweb.cs.cf.ac.uk/fun/welsh/ (from primary/primary)

I can't reproduce the issue, with 3.30 or 3.31 and default 
httrack settings (that is, I typed 
oldweb.cs.cf.ac.uk/fun/welsh/ as address and just pressed 
twice "NEXT") ; this is maybe a temporary server failure or 
something ? This is kind of weird, actually.

Can you retry using default settings, and/or try the 3.31 
release please ?
> 11:36:36 Error:  "Interrupted transfer" (-4) after 2 
> retries at link 
> oldweb.cs.cf.ac.uk/fun/welsh/*.* (from primary/primary)

Note that this one will never be downloaded (incorerct 
syntax spotted before)