Ringtone quality lowers after a few seconds ringing

[Guest ncruz]

Hi,

I'm having a problem with my monte carlo (from optimus, Portugal), the problem is that when someone calls me, the ringtone starts normally but after a few seconds looses quality, as if the speaker lost higher frequencies and the sound becomes more lower/bass.

This happens to me with the original rom, CM7 and Bluemonte.

I've already seen another Portuguese user complaining from the same, which leads me to believe that it isn't a hardware issue, but some kind of another problem?

Oh, last point, this doesn't happen always, in about 5 calls one has the problem, even with the built-in ringtones in each rom.

Any hints on what could it be?

Thanks to all!