My CSS Menu flakes out Overflow-X in Wordpress - css

Question

My CSS Menu pops the browser's horizontal scroll bar on and off as I hover over menu items. I've tried various combinations of css to deal with overflow using;
overflow-x:hidden;
and
overflow-y: auto;
But these just cut off my drop down elements in the menu and puts in a scroll bar inside my menu.
Here's my source code for the menu:
/* Main Menu*/
#menu {
font-family: 'sharetech', sans-serif;
float: right;
height: auto;
font-size: 18px;
padding: 0;
margin: 14px 0 0 0;
}
#menu a {
display: block;
line-height: 1em;
text-decoration: none;
color: gray;
padding: 2px 10px;
}
#menu:after, #menu ul:after {
content: '';
display: block;
clear: both;
}
#menu ul, #menu li {
list-style: none;
margin: 0;
padding: 0;
}
#menu ul {
position: relative;
z-index: 597;
}
#menu ul li {
float: left;
min-height: 1px;
vertical-align: middle;
}
#menu ul li.hover,
#menu ul li:hover {
position: relative;
z-index: 599;
cursor: default;
}
#menu ul ul {
visibility: hidden;
position: absolute;
top: 100%;
left: 0;
z-index: 598;
width: 100%;
}
#menu ul ul li {
float: none;
}
#menu ul ul ul {
border-top: 0 none;
top: 0;
left: auto;
right: -99.5%;
}
#menu ul li:hover > ul {
visibility: visible;
}
#menu ul ul {
bottom: 0;
left: 0;
margin-top: 0;
border-top: 4px solid #1b9bff;
text-transform: none;
min-width: 190px;
}
#menu ul ul a{
background: #1b9bff;
color: #FFF;
border: 1px solid #0082e7;
border-top: 0 none;
line-height: 150%;
padding: 10px 10px;
}
#menu ul ul li {
font-weight: normal;
position: relative
}
#menu > ul > li > a {
line-height: 48px;
}
#menu ul ul li:first-child > a {
border-top: 1px solid #0082e7;
}
#menu ul ul li:hover > a {
background: #35a6ff;
}
#menu ul ul li:last-child > a {
border-radius: 0 0 3px 3px;
box-shadow: 0 1px 0 #1b9bff;
}
#menu ul ul li:last-child:hover > a {
border-radius: 0 0 0 3px;
}
#menu ul ul li.has-sub > a:after {
position: absolute;
top: 50%;
right: 15px;
margin-top: -8px;
}
#menu ul li:hover > a, #menu ul li.active > a {
background: #1b9bff;
color: #FFF;
}
#menu ul li.has-sub > a:after {
margin-left: 5px;
}
#menu ul li.last ul {
left: auto;
right: 0;
}
#menu ul li.last ul ul {
left: auto;
right: 99.5%;
}

Answer 1

You were right Nix, it was in the pseudo classes. I figured it was, here's what was missing;
#fmenu ul ul li {
float: none;
width: 190px; <----set width
}
I defined a set width here and it solved the problem.