I have germinated three types of Corydalis, caseana, lutea, and nobilis, all using the same method. Sow them in moist mix, place in a sealed plastic bag, keep warm (20-25C) for at least one month. At this point, you will find that the seeds have expanded and burst the seed coats. Then they need 3-4 months of 40F (5C). When they germinate, they don't like high temperatures. They grow well at 50-60F for the first month or two. At 70F, you may lose them all.
The high temperature requirement at the beginning of the process is confirmed in Norman Deno's books on seed germination. A word of caution about Deno's method: when he says 70-40-70, he is saying that this is the temperature cycle which induces germination. He is not recommending that the seedlings be grown on at 70. For many seedlings, this is much too warm, and they will all die. He mentions this somewhere in his books. And in fact, the 70F after the 40F is not necessary even for germination. Many seeds will germinate and grow at 40F after the required chilling period. 70-40-70 is just the standard cycle that Deno uses to try to keep things simple, and because it works for a broad range of seeds.
With Corydalis, you may find that the seeds will germinate irregularly all through the warm and cold cycles. This is very inconvenient. I carefully dig out the seedlings before they make big roots, and plant them in small pots and grow them on under lights. This way, the ungerminated seeds can germinate at their own pace. I have attached a photo of two C. nobilis seedlings, one which germinated after one week of cold, and one which germinated after one month of cold. Both have been grown under lights at 50-60F. Seed was sown on 9/28/06. The larger plant germinated in the first week of November, and is shown on January 24. Quite the monster, isn't it? I won't be surprised if it blooms this spring.
By the way, I have C. nobilis seed from three different sources. One vendor kept the seed in moist storage since harvest. Only one lot of seed has shown any germination so far, and it is not the one that was kept in moist storage. That one lot of seed gave nearly 100% germination after one month of cold. It's all very mysterious.