[m2e-users] Why does this m2e update site say it's not available?

["KARR, DAVID" <dk068x@xxxxxxx>]

I checked for updates this morning, and the following update site said "No repository found".

https://repository.sonatype.org/content/repositories/forge-sites/sonatype-m2e/org.sonatype.m2e.maven.runtime.3.0.3/1.0.1/N/1.0.1.201106291304/

I imagine this site was added automatically, as I'm pretty sure I didn't add this manually.

I also don't understand why it thinks it's not available.  It's reachable by the browser, and it appears to have Eclipse plugin artifacts at that location, although I have no idea what the update site protocol requires.