"The ban was on account of Ravindra Jadeja not signing the renewal contract with the Rajasthan Royals and attempting instead to negotiate a larger financial contract with some of the other IPL franchises, thus resulting in a serious non-adherence to the IPL player guidelines."

Jadeja made the error of trying to gain a better deal with other IPL franchisees instead of first clearing his status with the Rajasthan Royals for whom he represented in IPL 1 and IPL 2. While the Royals did not officially let him go, neither did he sign on for a third year.
Preity Zinta Says, KXIP Team Not Sold to Hero Honda; Could Other Franchisees Be Selling?
New Franchisees in Fray for New Teams in 2011 IPL 4
Shiv Sena Retaliates against SRK and His Movie over Empathizing with Pakistan Cricketers
PCB Revokes NOC for IPL Even as Speculation on Abdul Razzaq Continues
Shiv Sena Threaten to Teach Modi Lesson in Their Language
Shah Rukh Khan Admits, There is a Problem , Feels Pakistan Players were Not Handled Well
Modi Announces Bonanza Auction for IPL 4; Change to Foreign Rule; Teams Can Retain Players
Preity Zinta Gets Her "Cricket" Show on Colours, Also an IPL Awards Nite Planned
IPL 3 Opening Ceremony Moves from Hyderabad to Mumbai
Shilpa Shetty, Lalit Modi: "We Owe No One an Explanation"
Pakistan Players in Lurch: Forget Cross Border Peace; This is Cold Blooded Business
Player Availability A Concern, Says Shilpa; Ness Hints At Australia
Franchisees Plead with Modi for No Major Shuffle/Auction for IPL 4
AP Sports Ministers Asks Deccan Chargers to Boycott IPL 3 After Matches Are Relocated
Lalit Modi's Global Plans for IPL Include Matches in USA and Abroad
Twenty20 Founder: "Let Twenty20 be a Curtain Raiser; Don't Overdo It"
Want an IPL Team in 2011 IPL 4 Season? Cough Up $225 and Then Some!