The front of nmap.org indicates the latest version is 5.20, but it's out of date. The download page provides 5.21. the 5.20 ebuild can be copied to 5.21, then delete the nmap-5.20 patch from the ebuild as they've implemented it upstream
*** Bug 302631 has been marked as a duplicate of this bug. ***
Please bump, 5.20 has ugly bugs that were fixed!
Fixed, sorry about the delay :)