Be interested to hear, I tried to use what was left over from the stock today and it had already gone bad...mixed it 1:7 and could hardly get any image at all after 3 minutes, it had been much quiker (1.5 to 2 minutes). Bottle was half full and was opened about 5 weeks ago. This would be a drawback for me, since there could be weeks between sessions.
Anyone else have these types of problems? With other paper developers - how do you work around this issue?