caption problem with ping.fm

I am using the pingpress plugin to automatically send my blog posts to ping.fm.

The problem is that if my post has pictures in it, the WordPress [caption] tag doesn’t get stripped (because it’s not html) or interpreted properly (because it’s not html) by the time it gets to whatever site ping.fm forwards it to. So the post ends up with things like this in it:

[caption id=”” align=”alignleft” width=”240” caption=”Image by tchuntfr via Flickr”] [/caption]

I tried reporting the problem to pingpress and ping.fm, but they seem to be saying it’s WordPress’ fault for not using HTML.

Is there anything that can be done about this?