Greetings
My initial tests were all with TinyMCE and just the WYSIWYG mode, and this also was occurring on a separate site, although neither were 'clean' installs, both were still fairly new.
In both cases, I copied the code directly from
http://www.kksou.com/php-gtk2/Joomla-Gadgets/googleMaps-plugin.php samples page and used the "addr" method and example:
{ google Maps addr="1600 Amphitheatre Parkway, Mountain View CA 94043" }
(...spaces added to try and have it display in this post)
The HTML modes were engaged when I was assuming that the editors were affecting things, but even without them turned on, the issue persisted on both sites.
It seems as if the conversion to HTML entities only occurs after the { } code. In fact if the { google Maps ..... } was the last thing on the page, code was ADDED after it was saved, and I'd get some extra < /P > or < P /> tags that would appear, even if there was nothing there. Anything after it gets wonky, nothing before it.
In both cases, the issue was with the demo version. I downloaded and purchased the regular version for my new site, and the issue went away. Also, before doing that, I had downloaded the Module version, and was able to use that on my sites without having the code issue ... so it was something to do with the invocation of it within an article.
So ... for now I have worked around the issue ... on one site I have a few errant characters that nobody has mentioned, and on my live site I have purchased the component and the purchased version does not exhibit the same behavior.