Providian Financial Corp., which has been plagued by  lawsuits and related bad publicity, said it had a net increase of 1.1   million accounts during the second quarter.   
In an earnings announcement Thursday, Providian said it had discovered a  "programming error" that had resulted "over a period of months, in the   billing of erroneous late fees related to specific weekend days." Providian   said it has fixed the problem, and took a one-time charge of $20 million to   cover the cost of refunds.       
  
"We believe that these incorrectly billed late fees were an underlying  cause of recent customer concerns," said Shailesh Mehta, chairman and chief   executive officer of Providian.   
The credit card company has been under investigation by the San  Francisco district attorney for practices related to late fees and   disclosure of fee-bearing product add-ons. Several cardholder and   shareholder lawsuits were filed over these issues, and the company   announced an enhanced "customer satisfaction program" in which it pledged   to refund fees customers considered unfair.         
  
Providian said its second-quarter net income doubled, to $126.5 million.  Managed loans grew by $1.9 billion during the quarter, to $16 billion.