Hi , Mrs. Anni,
I can not comprehend the issue you have with the writing
of an automation curve, running a Win 7 64 bit and Splat 64 bit with a
core i 7 here.
Have lots of tracks in different projects with at least 20 automation envelopes ,
more or less all written via typing the W- button (which of cause is shining red if activated)
for writing during playing and typing R for reading that curve afterwards.
Don´t know how I can help cause you are not writing about your system specs
and the Sonar version you are using .
It´s remerkable that this issue occurs now and not before.
regards
Pragi