Problem when I plug earphone....

My Sansa express i bought 1 months ago… I have a strange problem now.
When the earphone jack is fully pluged … I cant hear the audio clearly… its hears only the music part…and the sound is like coming from a tunnel… i have checked the EQ and its in the normal mode …and the voice is very low …its like karoake audio, no voice… but i have tried some other headphones …then it works… but those are big head phones …but i want to use the sansa earphone only… i donno why this like …

can I get any sansa support for this? will they help me for this issue?

i hv the same problem too,first i thought i was imagining and then it became more clear and i knew tht i’m nt,i tried to look up for sandisk headphones bt i couldn’t find and  i found out tht if iwant a new headphones i hv to buy a new mp3 bt my mp3 is working good i don’t no wht to do, irlly like the sandisk headphone and i don’t want to buy something else,i tried philips and others all were high quality sound and supre bass and when i tried them i was shocked there were no bass at all the sound was owful…