Sheaths on cattelyas

[pjoeverett]

some of my cattleyas are blooming or have bloomed and the second sheath on the plant does not bloom but the sheath dries up. Is there any hope of getting a bloom there again or will I have to hope that new growth produces a new spike and eventually a sheath and bud??
do the only blooms come from the newest growth even if they did not bloom in the past??