Thanks for the link, I had NOT seen that.
The only problem I see is that this doesn't appear to match (from a release date stand point) the most recently released software (this is from 2006).
In fact, If you look ftp://ftp.dlink.com/medialounge/DSM520/ you will see that this isn't even CLOSE to the most recent version.   I'm thinking that this is the 1.01  release (the original firmware).   
If D-Link were to release their most recent version of the software (or, to be honest, ALL the intermediate versions too) it would go a long way towards helping the community. 
I'd even purchase a 2nd 520 to use for testing on.