There have been some posts about when to replace the fuel filter, and there are some wildly varying mileages.

Volvo says to do it at 40,000 km (24,000 mi) and you may think "yeah right, make that 124,000 miles". So did, I. But while I was replacing the main fuel pump, I also replaced the filter.
Since I had replaced the old one myself and kept a record, I know it had done almost 69,000 km (43,000 mi).

Curious about the level of contamination, I tore the old one down and was in for a surprise. Shortly after, I had to replace the sender unit and primary pump in the tank. The surprise became even bigger.

So, first have a look at the tank of my 245 after 25 years:
http://i522.photobucket.com/albums/w345/jitter007/Benzinetank%20245%20na%2025%20jaar_.jpg

Looks clean, doesn't it?

Another look, two black specs of dirt. Upper centre: here's where the filter on the primary pump has been rubbing against the bottom of the tank.

http://i522.photobucket.com/albums/w345/jitter007/Benzinetank%20245%20na%2025%20jaar.jpg

So, that looks like almost no dirt at all, right?

All the more suprising, then, that the fuel filter looks like this after just 69 k km:
http://i522.photobucket.com/albums/w345/jitter007/ScanTech%2097.562%20benzinefilter%20vervuiling%20na%2069.000%20km.jpg

I think you can see why I decided to go for the recommended interval of 40k km in the future...