On-again, off-again plans for a Hyatt Regency in downtown Sacramento appear to be on again. Developers of the 16-story, 508-room hotel across from the state Capitol said they have settled a dispute that stopped construction just after the site was cleared. The dispute was over how profits would be shared among developers Joseph Benvenuti, Gregg Lukenbill and Robert Cook and limited partners Austin Ditter and Maxwell Freeman. Under terms of the agreement, the developers will buy the interest of Ditter and Freeman for an undisclosed sum. The hotel is scheduled to open in the summer of 1988.