You'd have had to be living on a desert island with no TV, newspaper or internet connection to have missed hearing about the great mutual fund scandal of 2003.
The issue was that some mutual fund companies allowed certain hedge funds to engage in after-hours trading, sometimes incorrectly referred to as market timing. Unfortunately, some companies have used the confusion about the term "market timing" to further their own cause. How?
They have used this issue to pretty much ban all forms of trading their funds, and some companies are imposing hefty short-term redemption fees