21.   But the problems could cause the company to default on its debt obligations, executives said.

22.   But there are a few problems that they have on their team and those problems have caused a mark on some of those other guys.

23.   But they argue that the problem could have caused far greater damage than it has and that, in any case, it will shortly be behind them.

24.   Doctors were looking for signs that a nerve problem is causing the hamstring discomfort that began last season.

25.   Especially in the Wells Fargo-First Interstate merger, computer problems caused problems for many customers.

26.   Fleming declined to say what problem had caused Williams to take leave.

27.   For riders, these problems have caused longer waits between buses on some lines or occasional disruptions in service.

28.   Gitner said TWA also experienced higher fuel prices and higher maintenance costs caused by problems with the mix of aircraft in its fleet.

29.   Graf did not mention the jeopardy her health problems have caused to her ranking, which appears destined to land on the durable shoulders of Sanchez Vicario.

30.   He said the failures of Braniff and Eastern airlines were caused by problems unrelated to their Kansas City hubs.