digital timer trouble

[beefORchicken]

so I've got some cheap noma digital timers from canadian tire to automate a few things.

running flourescents on one , no prob.
running 2 aqualifters and air pump causes it to reset when the timer turns off
(i notice when it doesn't cycle on again and the clock is reset from the last switch time)
same deal with another timer running a led system (2 adapters)

anyone else have this problem? quickfixes?