EDIT: An unofficial Bootstrap Modal modification has been built to address responsive/mobile issues. This is perhaps the simplest and easiest way to remedy the problem.
There has since been a fix found in one of the issues you discussed earlier
in bootstrap-responsive.css
.modal {
position: fixed;
top: 3%;
right: 3%;
left: 3%;
width: auto;
margin: 0;
}
.modal-body {
height: 60%;
}
and in bootstrap.css
.modal-body {
max-height: 350px;
padding: 15px;
overflow-y: auto;
-webkit-overflow-scrolling: touch;
}