Most likely is that the lounge and dining room are looped into the switched
live rather than permanent live at the hall light.
Assuming it is a standard pendent fitting, do the following:
1. Remove bulb and shade from hall light.
2. Unscrew rose.
3. Examine the wiring. There should be:
a) A flex to the bulb holder.
b) A cable to the switch (should be identified by having red tape or
sleeving on its black wire).
c) A number of other cables, probably 2.
All the earths from these cables should go to an earth terminal.
The other terminals are usually in a row, with the following layout.
Switched live should consist of a terminal block with 2 holes for bulb and
switch. One should go to the brown wire to the bulb holder. The other should
be one of the switch wires.
In the middle should be a terminal with permanent live. There are normally 3
holes, for feed in, feed out, and switch feed. The other switch cable
(usually the genuine red one) goes here, along with every other red wire
(usually an extra 2).
On the other side should be the neutral block, with again should have 3
holes for feed in, feed out and bulb. The blue from the lamp holder plus all
the black wires (except the red taped line from the switch) should go here.
If there are any discrepancies, this might be your problem. In particular,
you should ensure that the brown wire goes to the outside terminal along
with only one other wire.