Hi Neill,
We have discussed this topic a number of times, you can search for discussions of 'deep divers'. I believe Don Carlson posted a formula for evaluating bankruptcy probability.
The chart looks interesting, but there is little data available on the company here in the U.S. Deep divers are the achilles heel of AIM, in my opinion. My own preferred method is to evaluate the worst case I'm prepared to accept, and make that my stop loss. If you've lost all that you care to, enter a stop loss just below where it's selling now, if it's bottomed, you'll be able to ride it out, otherwise the market will take you out. If you're willing to ride it a little longer, set your stop loss just below wherever you think it likely to bottom worst case.