string_format rounding error..

Smarty Version: 2.6.0  (on debian stable)
There is a rounding problme with .xx5 on smarty's string_format:"%.2f" 
modifier.  This some times get correct, other times not.  I can't seem 
to find why this is, but here is code that should reproduce said problem:

    {% assign var="vat" value="0.525" %}
    {% assign var="total" value="10.95" %}
    {% math equation="x+y" x=$total y=$vat assign="total_total" %}
    {% $vat %}<br/>
    {% $vat|string_format:"%.2f" %}<br/>
    {% $total %}<br/>
    {% $total|string_format:"%.2f" %}<br/>
    {% $total_total %}<br/>   
    {% $total_total|string_format:"%.2f" %}<br/>   

Expected output

0.525
0.53
10.95
10.95
11.475
11.48

Actual output
0.525
0.53
10.95
10.95
11.475
11.47

-- 
Jonathan Lozinski
Senior Developer
 
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