USB Hub: Devices work only if connected one at a time

USB Hub: Devices work only if connected one at a time

Problem: On Crunchbang Linux with LXDE, when connecting my hub with three
devices attached to it, the computer recognizes the hub, but not all
devices. The Hub has no external power source. The devices connected are
as follows:
Keyboard -> USB to PS/2 -> Hub [takes longest, due to adapter
I guess] Wireless Mouse Reciever -> Hub [works fastest] USB powered
LED Light -> Hub [no initialization, just draws energy for 1 LED]
My Guess: The system tries to assign all devices at the same time and
fails to do this properly. What works is connecting one at a time: First
the Hub, then device 1, wait a moment, device 2, wait … device 4. Making
changes confuses the system even more, it seems.
I've tried this with different USB devices and also another hub – all with
the same results.
Question: Is there a workaround to make, say, USB devices connected to the
hub sign up one at a time with a little time in between; so I can connect
the hub with all devices as one?