A lawsuit filed last month by an Austin woman is the latest in a string of gender-discrimination cases brought against Dell Inc., the computer giant with a human resources department allegedly described by a Dell executive as “one of the toughest old-boy networks” in the company.

The latest lawsuit, filed Dec. 22 by Ellen Fleming in the U.S. District Court for the Western District of Texas, is at least the third gender-discrimination case brought against Dell since October 2008.

Fleming, a former level D-3 executive at Round Rock-based Dell (Nasdaq: DELL) who held several finance and comptroller positions during 10 years at the company, alleges she was treated differently from male counterparts and was fired in March 2009 after refusing to quit when she was demoted.

The lawsuit also alleges that Dell withheld her annual bonus because Fleming declined to waive her rights to file a claim against the company. The Harvard-educated Fleming is now teaching at the Acton School of Business in Austin.