"Shortcode" checkbox creates formatting problems

Hi, I have a very simple snippet which shows a “subscribe to us” email field and submit button. If I define it as a snippet, i.e. without the “shortcode” option checked (so that the full html is always pasted in to my posts) then it works.

http://i.imgur.com/X22SqHn.png

But If I take the same snippet and turn on “Shortcode”, and try to use the [xxx] designation in the post instead of the full HTML insertion, it messes up the formatting of the end result – puts spaces here and there, &nbsp’s, text lines overlapping each other and broken in half.

http://i.imgur.com/aotEbOU.png

Reverting back to shortcode off with the same code makes all the problems disappear. But I need to use a shortcode for this one so that it will be always up to date on all of our posts (i.e. not static html).

What can I do. Thanks

The code that the shortcode stood for is listed below.

<p style=”padding:10px 0px 0px 150px; width:450px;font-size:14px;color:#C63132;line-height:4px;”>Get our newsletter</p><!– padding is Top Right Bottom Left –>

<p style=”padding:6px 0px 6px 120px; width:450px;font-size:16px;color:#C63133;line-height:4px;”>and always stay updated.   Free registration</p>

http://wordpress.org/extend/plugins/post-snippets/