I've got the same problem. Originally with version 2.5 and then alsowith 3.0 after installing using the package you linked to. Here's my screenshot:
When I go to Favorites > Quick Connect the list is fine. It's just that Address drop-down list that has the Unknown entries.
Also, I don't know if this is normal or not, but when I'm managing my favorites and I remove an entry, I get a confirmation asking if I want to move an XML file to the recycle bin:
+- System -----------------------------
Microsoft Windows XP Professional
Service Pack 2 (Build 2600)
CPU Speed : 2794 MHz
Total Memory : 1022 MB
Free Memory : 531 MB
+- SmartFTP ---------------------------
Version : 3.0.1013.5
Time Stamp : 2008-04-17 15:35:02
Platform : x86
Unlicensed
Days in use : 267
+- Application DLL --------------------
sfFTPLib.dll : 1.5.13.4
sfFavorites.dll : 1.0.9.2
sfFavoritesShellExtension.dll : 1.0.1.9
sfTransferQueue.dll : 1.0.6.5
sfFTPShellExtension.dll : 1.0.4.2
+- Language ---------------------------
SmartFTP.exe : 3.0.1013.5
+- Internet Explorer ------------------
Version : 7.0.5730.11
+- Winsock ----------------------------
Winsock : 2.2