This is because from a fresh BugNET install using the automatic installer, the EnableGravatar setting is not inserted into the HostSettings table:
Data.HostSettings.sql
To sort this out manually just manually insert the EnableGravatar host setting in your bugnet database:
Data.HostSettings.sql
To sort this out manually just manually insert the EnableGravatar host setting in your bugnet database:
INSERT INTO [BugNet_HostSettings] ([SettingName], [SettingValue]) VALUES ('EnableGravatar', 'False')