I've not had any problems downloading anything from PES (even old files)
Ever since Xargoth-Teran, Xenius and Eswen have taken over as staff at PES it seems to be acting normally to me.
PES is functioning perfectly, as far as I can tell. However, fileplanet seems to be the problem, which is what was often used for the larger files. Are you having success with the mods linked to fileplanet from PES as well? For me, it comes up with a missing page alert from ign. If you're having no trouble with it, can you let us know what browser, operating system you're using?
For example, try this one:
http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=7219&id=765
An attempt to download should come up with this image: http://www.automatichamster.com/keening/forum_images/error_404.png