I used to review pension funds when I was in practice, and had the misfortune of getting involved in some funds with the biggest deficits in the land (into the billions of pounds).
The short answer is if you are in final salary scheme, pay it. As a %age rise yes it is high, but in absolute terms it is peanuts. Final salary schemes are topped up by the company in the first instance in almost all cases. One that I worked on was contributing 75% of employee's salary to keep the fund in the black. I would ask what the employer's contribution rate has gone up by, and try and ensure it is in line. If not, speak to the trustees (who should be working for you) and ask them why not.
I had never started a pension because as per Tim's comment I got fed up with dealing with millions lost (and I mean vs the markets, not just inline with markets) and seeing fund managers get paid millions. I have now started one to get the tax breaks in saving and the employers money, but I have stuck half in cash and half in high risk stuff. Avoid the norm as that is where the bulk of monies are so easiest to get lost in the performance figures IMO.
Sarnie, if you have 4 properties then nice one. I have tried a few times to stick money into it and at the moment (at least in the places I know) it doesn't stack up. South of France is my next stop in July to buy.....