After having been set to something other than "None", can the default filter for individual groups, and groups of groups, be reset to "None".
"None" is not listed as a optional selection in the "Filters that apply to this group" section of the group options menu. And the last selected profile continues to be displayed in the Groups List window, rather than "None", after unchecking the box for "Use Profile".
I presume that the change could be safely accomplished by editing the nbi.ini file, but I don't know what specific settings in the group and groups of groups blocks need to be modified or deleted, or that doing so won't cause problems.
Using the following sample group, and group of groups blocks in an nbi.ini file for reference, can the desired change be accomplished by deleting the line "FilterProfile=Custom1" (As "None" doesn't seem to be a recognized designation), and changing the line "UseProfile=1" to "UseProfile=0" in each block?
[NewsgroupTitle]
Active=1
DisableAutoRAR=0
DisplayAge=0
DownloadPath=D:\Newsbin-Downloads\
FilterProfile=Custom1
LastAccess=1306737432
PAR_AutoDownload=1
Parent=GroupOfGroups-1
ShowFilters=0
ShowNew=0
UseAutoMode=0
UseFTR=0
UseMDA=0
UsePath=0
UseProfile=1
[GroupOfGroups-1]
Age=0
ColumnDir=1
ColumnSort=3
DisableAutoRAR=0
DisplayAge=0
DownloadPath=D:\Newsbin-Downloads\
EnableFilters=1
FilterProfile=Custom1
IsExpanded=1
MaxSize=0
MinSize=0
PAR_AutoDownload=1
ShowCompact=1
ShowFiles=0
ShowFilters=1
ShowNew=1
UseAutoMode=0
UseFTR=0
UseMDA=0
UsePath=0
UseProfile=1
Xpost=0