When using a local NuGet server, whenever I try to install an individual package from that server, all I get is this error: “The remote server returned an error: (404) Not Found.”

The packages are all there in the filesystem and the feed itself sees all the packages appropriately. I can even browse the package directly!
What am I missing?
I did just upgrade from NuGet server 1.4 to 1.5, but I’ve seen this happen before. Touching the package files used to help, but that does not appear to be the case now.
EDIT: Actually, I hadn’t seen that exact error before…I’ve seen this one, intermittently, that touching the package tended to fix.
sigh…
http://blogs.thesitedoctor.co.uk/tim/2011/09/02/Nuget+Server+On+IIS6+Returns+404+When+Downloading+Package+After+Upgrade.aspx
EDIT: In case the link ever dies…I am hosting my NuGet server in IIS6, which wasn’t set up to properly handle extensionless URLs. And since the semantics of downloading individual packages changed from a direct file link to an extensionless route, I started getting 404s. Adding the wildcard mapping described in the article fixed it instantly.