QuickSilver (as of b52) only seems to index the last profile, when sorted by names.
So, to index your default profile simply rename its first part (e.g. 'ags7sd6' in 'ags7sd6.default') to something that will appear last among your profiles (e.g. 'zzzzzz').
To index all profile, you could create a fictitious profile and a script to merge all the individual bookmark files. Or wait for the QS plugin to be upgraded and be smarter.