Forex's transaction is illegal?

Although Mesyuarat Ahli Jawatankuasa Syariah Negeri Perak has made ruling that transaction Forex is legitimate(halal), nevertheless there were some thing of could cause transaction Forex this be illegal that is:

* Overnight / swap charge or maintainance charge.

Reference: http:/ / mufti.perak.gov.my / difficulty / Difficult_utama.htm (refer question from Fakhrunnazim Muhajir On Feb 15)