Div Hidden Behind Another With Web User Control

I am having some problems with my DIV, it wont display over a a DIV that has a web user control in it. Below you can find my css. I believe I have done everything right and am hoping that someone can maybe see an error that I have made and help me out. If you need any other code let me know. I also wonder if its just IE rendering it wrong?

{
background: #ececec;
position:absolute;
top: 236px;
left: 201px;
height: auto;
width: 280px;
border: solid 1px gray;
z-index: 50;
text-align:left;
padding-left: 5px;
padding-top: 5px;
padding-bottom: 15px;
font-size: 8pt;
}

The Activity DIV (same the div above just changed position)

{
border: solid 2px #A9C5EB;
position: absolute;
top: 353px;
left: 290px;
width: 710px;
height: 227px;
font-size: small;
overflow: scroll;
overflow-x: hidden;
background-color: #F8FBFE;
z-index: 2;
}