Why do my energy saving lightbulbs flicker on and off even when i turn them off?

I have three lights in my room and i recently changed them to energy saving bulbs. They are all the same type of bulbs (philip softone 20W effective light to 100W non energy saver) i have two lights mounted on the wall an one in the middle and it has only been the one in the middle that has lit up strangely, only at night i may not have noticed on the walls though. Is this normal?