Here is my experience from installing directadmin on FreeBSD 6.1.
Installed cvsup via ports
Updated os source and ports via cvsup
Had the usual wget licence error so I followed the 5.x instructions in the link below which also didn't work (I didn't expect it to but why not try it). Then I copied back the origional wget file (installed by directadmin) and it worked fine so maybe give this a go if you have the same issue. Don't ask me how it worked as I can't still work it out:
6.1 with DA works in the same way as 6.0, if you had problems expect the same ones in 6.1 if you didnt have problems dont expect any in 6.1
Steve had the same problems as me with wget and group admin, I forgot all about the admin problem when previously posting here and cant remember if it also happened in the 5.x version but I believe it does.