Hi skiv71
To solve this problem you have to edit the mailing_lists.shtm file and remove the document.onmousedown line in "function scheduleInit()":
    function scheduleInit() {
        var tbody = $("scheduleRows");
        var i, tr, td, hour, j, tbl2, tr2, td2, k, content, title, intId;
        for (i=0; i<24; i++) {
            tr = appendNewElement("tr", tbody);
            td = appendNewElement("td", tr);
            hour = ""+ i;
            hour = ("00"+ hour).substring(hour.length);
            td.innerHTML = hour +":00 - "+ hour +":59";
            
            for (j=0; j<7; j++) {
                td = appendNewElement("td", tr);
                td.className = "ptr hreg";
                td.style.paddingLeft = "3px";
                td.onmouseover = function() { hourOver(this); };
                td.onmouseout = function() { hourOut(this); };
                td.onmousedown = function() { return hourDown(this) };
                
                content = '<table cellspacing="1" cellpadding="0"><tr>';
                for (k=0; k<4; k++) {
                    if (k == 0) title = hour +":00";
                    else if (k == 1) title = hour +":15";
                    else if (k == 2) title = hour +":30";
                    else title = hour +":45";
                    intId = getIntervalId(j, i, k);
                    content += '<td id="ivl'+ intId +'" style="padding-right:2px;" title="'+ title +'"';
                    content += ' class="qreg qon" onmouseover="quarterOver(this)" onmouseout="quarterOut(this)"';
                    content += ' onmousedown="quarterDown(this); return false;"> </td>';
                }
                content += '</tr></table>';
                td.innerHTML = content;
            }
        }
        
        document.onmousedown = function() { return false; };                                             // DELETE THIS LINE TO ENABLE THE ONMOUSEDOWN FUNCTIONALITY
        document.onmouseup = function() { mouseDown = false; return false; };
        document.onselectstart = function() { return false; };
    }
Regards! :D