I have some information on this that may or may not be relevant. I have been having problems with the search function on a recently installed XFCE CE version - the quick search bar was greyed out. I decided to do a Synaptic reinstall. When I removed Synaptic it also removed aptoncd, jockey-gtk and language-selector.
I reinstalled synaptic but the search bar was still greyed out. I then reinstalled aptoncd which pulled in a lot more dependencies (mostly from gnome although I didn't make a note of them, there were too many, 30+Mb). When they had finished installing however the search function in synaptic was restored, so obviously something in the aptoncd dependencies is a necessity for the correct functioning of Synaptic. Unfortunately I can't tell you which one it is.
Fujitsu Lifebook AH532. Intel i5 processor, 6Gb ram, Intel HD3000 graphics, Intel Audio/wifi. Realtek RTL8111/8168B Ethernet.Lubuntu 13.10,Ubuntu12.10 (Unity), Mint16 (Cinnamon), Manjaro (Xfce).