Sensing tilt using accelerometer alone

Well, by strange I mean that I am unable to get 2 rotations together at the same time.
The third rotation, which is in the direction of g will never be obtainable, I understand that.
However the other 2 roatations should be obtainable.
Here is how it happens.
I hold the accelerometer on my palm facing up. The x axis is aligned along the fingers and y axis is perpendicular to it
If i rotate about the x axis, I get a proper 0-360 degree value, but while this is happening I do not get any change in y, and then i suddenly jump by 90 degrees in y.
while i do the rotation about y axis, i get a similar thing going along the x axis, but the jump is of 180 degrees.
and the code is just what i posted above, xforce - it is just the value of the force vector along x, force being gravity.
I have already done the calibration, subtracted the zero g values etc.
I was just curious if someone has tried it here the way smart phones have used the accelerometer.
I might be able to figure out a way...
Thanks