Hi. I happened to upgrade to 6.04 x64 last week and only had reason to use it today. I noted that my existing Friendly names weren't displaying in a scan, even though they always did (and the list is still present, I checked).
So I looked at the download page today and saw 6.05 with this note: "Fixed an issue with MAC-based friendly names during rescanning and adding new names." I figured that HAD to be the issue (even though I'm not adding new names--this is all existing), but wouldn't you know it, they still don't appear in a scan with 6.05.
Check the Network Scanner's config file netscan.xml under the Documents folder or in the application's folder.
Open it in Notepad and find a section like this
<value>My MAC address</value>
Most likely the MAC address lines contain dashes or colons, because of an issue in the earlier versions of the software. Simply remove them, that is change AA-BB-CC-DD-EE-FF to AABBCCDDEEFF and it should work fine again.