Taxonomy select's lose data on non-ajax submit...

There are several conditions under which taxonomy selects can lose their data. The ones I've observed so far are typically using non JS versions of AHAH'd workflows...

test conditions:
Create a Vocabulary, Foo with terms foo and bar.
Associate Vocabulary Foo with Content Type Story
Enable upload.module.
Enable attachements for Content Type story.

To reproduce with core:

1. disable JS with in your browser.
2. goto node/add/story
3. select bar from foo vocabulary.
4. upload a file with the attach button.

I observe that the taxonomy selections are lost on the next page. This error can also be reproduced with CCK's add another item for unlimited value fields, or the file field upload button or on node edit forms. However on a node edit for it will revert to the original values, instead of blank.