Lighting Problem?

I replaced a 3ft fluorescent tube (ceiling) with a new 6ft one. The wires on the old 3ft were as follows: 3 earths, (noneof them sheathed), 3 blacks, one of which had red masking tape that i assume to be a switch live and 2 reds connected to one of those white plastic blocks.
I repleced the wiring like for like, noting down what went where etc and the tube works fine ......however I now have the following probs:
1: another 3ft tube in the kitchen doesnt work at all when the 6ft is either on or off, starter and tube are fine.
2: the light in the shower room outside doesnt work but when the 6ft tube is switched off and the cord in the shower room is pulled on both the 6ft tube and the shower room light flicker.
any suggestions?