41.   But officials caution that the pingers may have been separated from the boxes during the crash.

42.   But officials cautioned that they were not close to a final deal on that and other elements of a package of changes for the system.

43.   But Pentagon officials caution that while the numbers may converge, the missions radically diverge.

44.   But the officials also cautioned that a raid to capture Karadzic is not imminent.

45.   But the officials cautioned that individual al-Qaida operatives and their associates in the decentralized group might still be able to launch smaller terrorist attacks.

46.   But the officials also cautioned that the chances of the Taliban bowing to the American demand were slim.

47.   But those same officials cautioned that sticking points remain, and that agreements in the Capitol are always subject to last-minute objections.

48.   But these officials cautioned that it is impossible to make a blanket assertion that al-Qaida possesses no nuclear material.

49.   But the official cautioned that it was not clear that any equipment had actually been delivered.

50.   But the officials cautioned that some of their information was contradictory and that the cause of the crash remained unknown.