Thanks to all for the nice kind comments !
My plant is surprisingly easy to grow. In fact I don't see anything special ; it usually flowers twice a year, making two or three blooms. This hasn't occured for a while because I somehow gave up growing and just keep my remaining plants alive, until Sept. 2005, when I decided to go back to growing (this is definitely a 'harmful' virus :rollhappy: ). And this plant survived (so as my armeniacum) to a relative dryness, some colder conditions (with even some 11-12°C at night), in an used medium... I know, this is very bad...
Now it is grown in I/W temps, bright light (I always thought this was an important point to successful growing for at least this species), and maintened evenly moist (sphagum/bark/seramis medium). Winter temps are a bit cooler - and waterings thus reduced -, but I don't think this is absolutely necessary.
No secret, it likes calcium ; I used to add calcium carbonate to the growing medium twice a year. But I'll turn my plants in rockwool (already done for my primulinum, and God, this is breathtaking, strong new roots developped within a week !!). So all the nutrition program will change. I'll keep you informed of the results ;-) !