I fly to Madeira often and couldn't land in two occasions, had to go back to mainland and try the following day. The main problem in Madeira is the wind and the feeling of landing there when is windy is that you're going to crash.
TAP doesn't risk it as much as other companies when it's windy (they had a fatal crash in Madeira in the 80's) and that's why sometimes they don't land while others do.