I have never had any problems with my rover 75 diesel tourer. I must say I have never heard of this problem. The 75 I drive has done 98500 miles with not a single fault, currently knocking up 2000 miles per month..
The strange thing what I find about my diesel is the fuel ecomomy is getting better and better with age?....£40.00 will do 450/500 miles and I never turn my auto ATC off since I have had the car 2002. I have read in other sections of this site that the fans go after 60.000 miles.
If that is the case mine must be built by NASA. However IF the fan on mine has gone then maybe the diesels don't require the extra coolong a petrol may need and so no problems occur.