The problem the USPS is having is not about prefunding pensions and pension plans. Their problem is that they are required to fund future employee health care benefits. No other company in America - public or private - is required to do this.
This is a side note, but... By the way, I am actually a frequent reader of your blog, and I really miss your posts on economics. Link for the curious:
After googling this, you appear to be correct. However, the problem is not that the USPS is required to do this - the problem is that everyone else is not.
There is absolutely no reason to treat pension and non-pension obligations differently, and the fact that we treat the USPS differently than everyone else is not an argument to let the USPS off the hook. Instead, we should force both the public and private sector to properly fun their post employment obligations.
As for the blog, I'm building a startup, and haven't had time to post. I'm planning a post on color measurement soon, however.
This is a side note, but... By the way, I am actually a frequent reader of your blog, and I really miss your posts on economics. Link for the curious:
http://crazybear.posterous.com/
Good stuff!