Unable to control external speakers connected using 3.5 jack

I have the same problem as Kumaranhere.
Mine TV is a Series 3/350 32"
I have connected 2.1 speakers using the 3.5mm jack. I have set the TV audio option to "external speakers" When I try to adjust the volume with the television remote, I get a message which reads "option not available." Alternately, if I set the TV audio option to "Television speakers," sound is still coming out of the external speakers, only, but adjusting the TV volume has no effect on the sound.