whenever i tried to open Synaptic package Manager the following messages shows:

E: Type '.net/tualatrix/ppa/ubuntu' is not known on line 2 in source list /etc/apt/sources.list.d/tualatrix-ppa-maverick.list
E: The list of sources could not be read.
Go to the repository dialog to correct the problem.
E: _cache->open() failed, please report.

Ubuntu Software Center, Update Manager, Synaptic package Manager all are jammed and indicates the same error. Except these everything works perfectly.

How to fix this?? please please anyone help me..