Div keeps moving down the page when opened on different computers - css

Question

Okay so this is quite hard to explain but basically I position the title div perfectly so that it is centered in the header div.
It remains in this position on some computers.
However, on other computers it jumps further down the page - even with the same positioning attributes. (This is tested on the same web browser.)
I have tried with absolute, relative etc. positioning, still no luck!
Note: This div contains text.
CSS:
#header {
position:relative;
height:170px;
background-color: #30A7BF;
margin:0px auto;
padding: 1px;
}
#title {
position: relative;
top: -20px;
left: 315px;
}
Thanks!

Answer 1

Hi is difficult to understand exactly your issue but I can give you a few tips to have a nice center vertical and horizontal:
For horizontal alignment you can use display:inline-block if you want all the div centered:
#header {
text-align:center;
}
#title {
display:inline-block;
}
For vertical align use line-height equal to the total height
#header {
line-height:170px;
}
This only work for one line text if you want another option tell me
And the demo here http://jsfiddle.net/8JLzy/7/
Edit
To work with a text of more than one line you can do this : First your html add a wrapper inside #title:
<div id="header">
<div id="title">
<div class="center">Your Title</div>
</div>
</div>
And on the CSS work with display property:
#title {
display:table;
height:100%;
margin:auto; /*Make the horizontal*/
}
#title .center {
display:table-cell;
vertical-align:middle;/*Make the Vertical*/
}
New demo http://jsfiddle.net/8JLzy/16/

Answer 2

use line-height, not position:relative
#header {
/*position:relative;*/
height:170px;
background-color: #30A7BF;
margin:0px auto;
padding: 1px;
font-size:1em;
}
#title {
line-height:0.5em; /* for example, or instead use padding-top: */
padding-left: 315px;
}