I experience this same problem. When browsing around the end of an 800 page PDF, xpdf will consume 250MB/sec! Also, it is very slow. I have manually downgraded xpdf from 3.04-13 several times on different computers because of this bug. Is xpdf abandoned? I understand if it's difficult to update to 4.0x but xpdf has been essentially unusable since January.
If I go through the trouble of generating the one-line patch that will fix this bug, is there anyone out there that might apply it and issue 3.04-14? - Greg