There has been much random speculation ever since the ICC has notified that Mohammad Asif has withdrawn his appeal against the suspension. But here is the real reason why.

The ICC caused quite the stir when they made a press release to the effect,
Mohammad Asif confirmed earlier today that he has withdrawn his challenge to the provisional suspension imposed on him on 2 September 2010 pending determination of the charges brought against him under the ICC’s Anti-Corruption Code.Arrangements are now being made for the challenges being made by Salman Butt and Mohammad Amir against their provisional suspensions to be heard in Dubai on 30 and 31 October 2010.
The already frenzied rumour mongering suggested that Asif had developed cold feet ahead of the ICC hearing amidst swirling rumours that Aamer may talk.
However, Asif himself has had to clarify the issue. And contrary to speculation that he is guilty of the spot fixing allegations from the England Pakistan series, the Pakistan fast bowler is suggesting that the ICC is responsible for the withdrawal.
Asif claims that the decision was made with the intent that his lawyers will be able to comb through the vast amount of data, apparently released by the ICC, before they can fight his case. While he will not be at the hearing along with Salman Butt and Mohammad Aamer, Asif may use a later date to clear his name, which he says he will.
The ICC have also rethought Asif's decision because Asif's absence now means there is no problem for the ICC to tackle the two Pakistan cricketers at the ICC headquarters in Dubai, a place where Asif has been banned from entering over a previous drug possession situation.
Asif appears to be either taking a wait and watch approach or weighing his options when one looks upon his decision. The appeal is being made by the other two Pakistan cricketers to clear their name at the earliest. Time, however, is perhaps not hasty enough for Asif. It remains to be seen what the troubled cricketer does next.