> I had configurated WinHTTrack to 'Go everywhere in the 
Web'

Never use 'Experts' option - here use the 'Set 
Options'/'Scan rules' features, such as:
+delivery.acm.org/*crawford*

> 15:35:03 Warning:  File has moved from
>
portal.acm.org/ft_gateway.cfm?id=944223&type=html&dl=portal&dl=ACM&CFID=12230956&CFTOKEN=7
0721556
> to
> <http://delivery.acm.org/10.1145/950000/944223/p5>-

Any error or warning aftre that?
Try the scan rule (and let experts tab with default 
values!), this should do the trick