Without seeing the code for your head.tpl file, I can't say for sure, but from the code I can see, I think in your head file you have an extra table in there that doesn't seem to be doing much.
Have a look for something like this:
Code:
<TABLE cellspacing="0" cellpadding="0" border="0" width="100%" height="18">
<TR>
<TD>[img]/shop/skin1/images/spacer.gif[/img]</TD>
</TR>
</TABLE>
</TD>
</TR>
</TABLE>
The height of 18 seems to be about the height of your grey bar, try commenting out this table, or the row in it. (If it was me, I would alter the 18 first to see if it makes a difference, then you would know it was the right bit).
If this doesn't help, put your head code in a reply.