Why is xpdf super slow under Xqt, when using the pdaxrom package or chrooted under debian?

I have pdf files roughly 5-6 megs in size of 24 A4 pages. xpdf takes forever to load the file, like 15-20 minutes, ridiculous, it's unusable.

However qpdf under Qtopia, which is based on xpdf, loads them right away. However many times it crashes when displaying pages with certain focus and so, so I want to use something stable.

I had pdaxrom flashed for a while and there the xpdf loaded the files right away like qpdf does, so it can't be that the Z is too slow for it or something.

So why is this?

I thought maybe it's something like the Z tries to render every page in memory when reading the xpdf but there is no setting to disable something like this xpdf or is there? I have 512 megs of swap set up so that's not a problem.

What's the issue?