Well I have to leave for the afternoon, but I have so far found that removing the following code from postbit.css will stop the inbuilt vbulletin resizer from working, and allows this mod to work again - but it only appears to work in the blogs and not in the posts. I'm using postbit legacy, but perhaps someone can confirm it doesn't work in postbit also ? There must be something i'm missing - anyone have any ideas?
Code:
.postbit .content img, .postbitlegacy .content img, .postbitdeleted .content img, .postbitignored .content img, .eventbit .content img {
max-width: {vb:stylevar postbit_content_max_image_width};
_width: expression(document.body.clientWidth > {vb:stylevar postbit_content_max_image_width.Size}? "{vb:stylevar postbit_content_max_image_width}": "auto" );
}