Robohelp does not recognize border css

My .css is with the following configuration:

img (
border: 1px solid # 006699;
margin-left: 40px;
)

When I insert an image in Robohelp it does not recognize
the border .css, the code is as follows:

<img src="../../car.png" alt="" width="16" height="16" border="0" />

if I remove all the properties:

<img src="../../car.png">

the border appears. But then inserts Robohelp these properties
again.

There is a solution for this?