I have come across a dozen or so ESS modems ESS2838 chipset which stopped functioning on Feb 21st , modems continuously attempt to dial out before getting dial tone after this date hass passed. A fix is available at the ESS web site at :
http://www.esstech.com/techsupp/drivers.shtm#comm
and a FAQ is available at:
http://www.esstech.com/techsupp/faq.shtm#no-dial-out:

http://www.esstech.com/techsupp/drivers.shtm#comm
and a FAQ is available at:
http://www.esstech.com/techsupp/faq.shtm#no-dial-out: