Is it only the Getting Started Guides that you cannot download? If you aren't having issues downloading PDFs from other locations on WebAssist, then this might help us pinpoint the cause of this. We made a few changes a while back to resolve any PDF issues, but it seems as though a few users are still having problems.
As a quick test, i have copied these three files to the How Tos directory. If you can view these, then we'll try to take a look at any differences between the two locations.
Let us know if this works.