corporate-ir.net is a utility domain that only exists to serve customized investor relations sites. The base domain itself actually does nothing. Think of it like github.io... www.github.io serves no purpose in itself.
phx.corporate-ir.net was a major upgrade to corporate-ir.net done around 2003, called phoenix. That's why there's the strange phx subdomain in front of the domain. Apparently that was the last upgrade they did to this service... and its neglect is most likely the result of a couple of acquisitions.
corporate-ir.net was created by a company called CCBN (ccbn.com). They were purchased in the 2000's by Thompson, which then merged with Reuters. Thomson purchased CCBN for a different product (not corporate-ir.net) that was strategically important to their business. So its not really a surprise that they haven't put much TLC into the way that the domains resolve -- this investor relations website business is peanuts compared to Thomson-Reuter's core competency.
www.google.com/search?q=corporate-ir.net