One ring to voicemail fix???

[cruise350]

Is there a fix to the one ring to voicemail problem. My problem is that most times my phone only rings once and then goes to voicemail before I can get to it. When I ask the caller they say they only got one ring too. Sprint says there is nothing they can do. Is there a mod to the EPST that I can do to force it to ring a certain amount of times before it sends a call to voicemail. . I've read other posts where people have had this problem. Should I exchange my phone? Are more than just a few people having this problem? I am running a stock rom, with only the tethering mod installed and some games. No major hacks.