[scribus] automatic unwanted downsampling?

[vwf]

Hello,

I have some png-images with high resolution (>600dpi, >2000x3000px).
When I include them in a document and export to pdf, the output is
correct. When I reopen the document the image is downgraded to something
like 200-300dpi, and the exported pdf has the same inferior resolution.
Is this a bug, a feature, or something else? I would like to keep my
precious sharpness.

All with scribus 1.3.5RC2 / Debian Lenny.

Thanks,
Frits