Hi Julian,
I have never seen something like this. The problem is that the project file (.xosm) does not define any process instance. PI crashes because the .xosm file does not provide the processes that should have been stored in the processing histories of each view. For example:
<ImageWindow currentView="wednesday30nov11" ... >
<MainView id="wednesday30nov11" ... >
<initialProcessing/>
<processing historyIndex="16"/>
the <processing> tag tells that the image "wednesday30nov11" has a nonempty processing history and the current state of the image corresponds to the 16th history step (the "historyIndex" attribute). However, the tag is empty (we know this from the closing slash: "/>". When PI loads this project, it expects to read at least 16 process instances but there is none. This is theoretically impossible and I didn't write the code robust enough to resist this event (I should).
The same applies to all images (including previews), to the states of all process insterfaces and to the icons: there are no process instances defined in this .xosm file. The icons will load, but with default parameters for each process. I'm sorry... I have edited the .xosm by hand to let you at least load the images; you'll find it attached to this post.
Can you figure out why this has happened? It is theoretically impossible (well, actually, it *is* impossible looking at the code) for the project generation code to write a .xosm file without any instances if there is one processed image. I'll have to investigate this very carefully.
Sorry again...