I thought the 40-bit keys were used due to cryptographic export restrictions, and not lack of randomness?
http://en.wikipedia.org/wiki/40-bit_encryption
Seems to agree with me.
http://en.wikipedia.org/wiki/40-bit_encryption
Seems to agree with me.
They link to this page with more details: http://www.cs.berkeley.edu/~daw/papers/ddj-netscape.html