V Pak Chong spike / bud drying up? help!

[stefpix]

Hi
I have a Vanda Pak Ching. the little spike grew to a vouple of inches but now it looks like it is drying up...

I wonder what would be the cause.
It hangs on a southern window gets good sun a few hours a day - supplemented with CFL.

It is growing new roots and those look good.
I wonder if the humidity drop caused this.
In the summer I had 60 % or more now just 30/40%. should I mist more in the future? isn't it bad to mist in between leaves?
for this may be too late but in the future?

thanks
stefano

ps but at least my Spathoglotthis plicata's spike seems getting on the way to the finish line! and the Phal equestris' too