Question on translate() function

I am using the translate() for some operation looks like I am getting
something I am not expecting .. Am I missing something?

I am making the following call to the custom function :

<xsl:value-of select="k7:replace-chars-in-string('if($xyz-(abc-bcd)')"/>


Function definition ..
<xsl:function name="k7:replace-chars-in-string">
<xsl:param name="string"/>
<!--examples :
$xxx,
,$xxx
($xxx
$xxx)
=$xxx
$xxx=
$xxx*
*$xxx
$xxx-
-$xxx
+$xxx
$xxx+

$xx+$yy-$zz

returns
#xx
or xx#
or #x#yy# etc.. replaces the operators after/before the stringto '#'

-->

<xsl:value-of select="translate($string ,'()''+-*$=' , '#')"/>
</xsl:function>


What I get is : if#xyz#abcbcd


What I was expecting / I want : if##xyz#abc#bcd#


Thing that is perticularly bothering me is abcbcd and not abc#bcd


My understanding about the translate() function is that the second param is
the list of chars you want to replace, the third param is the char you want
to replace with. SO I was  hoping that

()''+-*$=b will all be replaced with #


dakT