Update: Nope it ain't broken. It was purely operator error on my part - I missed an "=" sign in the .html for a component, and that was borking file uploads. It was weird, because Safari and IE would upload just fine, but Firefox would barf.

Josh just discovered a weird behaviour in Pachyderm, where uploading files was breaking. But only on Firefox. WTF?

A quick google brought up this post on NSLog.org, via ryfar.com:

I implemented today a generic component for file uploads to my application and got "no form data left" errors from WOFileUpload.

System.setProperty("WOUseLegacyMultipartParser", "YES");
Update 2: Looks like the code mentioned above may break things rather than fixing them. We've removed it, and things are sorta working again. And, King found one cause of the exception we were seeing - a missing = sign in the name="myButtonName" for the submit button was causing FF to barf violently. But, we're still seeing a separate upload problem...