It's worth noting, that there are some fairly famous women in computing.
Augusta Ada King, Countess of Lovelace (wrote the first computer program)
Rear Admiral Grace Murray Hopper (found the first (literal) bug in a computer, Wrote the A compiler (one of the first compilers) in 1952, worked on the design team for COBOL, worked on standardization of COBOL and FORTRAN)
Roberta Williams (Video game desinger for Online Systems (AKA Sierra Online and Sierra Entertainment), best known for writing most of the "Kings Quest" series, "Phantasmagoria," and "Mystery House" (which was the first graphical adventure game))
Sally Floyd (best known for her work on TCP/IP, notably Random Early Detection, Selective Acknowledgement, and Explicit Congestion Notification)
Women have made some seriously large contributions to computing, so I can only conclude that women are more then capible in this field, ergo the lack of women in computing must be socital pressures which discurage female involvement.
From everything I can see mysoginistic attitudes (some of which are present in this thread) seem to be a considerable problem. If you have a duragitory comment about women in computing, do us all a favor, keep it to yourself.