Problems uploading in latest browsers

I think a lot of you might have run into this already, but it seems like TiddlySpot has a problem with newer browsers. If you download your site and work on it offline, you will probably find you can no longer upload it back to TiddlySpot. You can however continue to update, ie 'save to web', your TiddlySpot site while using it online. It's only the 'upload' functionality from a local file that's broken.

The reason (I think) is that newer browsers have tightened up the security rules on what is permitted from local files. The restriction prevents UploadPlugin from doing what it used to be able to do. The problem is not specific to TiddlySpot but would effect anyone using UploadPlugin to upload from a local TiddlyWiki to a server.

I'd love to find a work-around or fix for the current UploadPlugin issue. So if you can help with either of these then please let me know.