Multi measure rests vertical positioning

[Werner]

Hallo,

I often used just r1 instead of R1 in 4/4 and 2/2 time.

Now I thought, it would be good, to use the horizontally centered full-measure 
rests. BUT:

I write two voices in one staff. For a while the lower voice plays quite high, 
the higher voice rests for some measures.
The r1-rests are printed always "a quint higher" than the lower voice's notes.
The R1-rests are printed always at the top line of the staff, but that makes 
collisions with the notes of the lower voice.

Unfortunately it seems, that the lilypond default is ugly in that situation.
also threads 
http://thread.gmane.org/gmane.comp.gnu.lilypond.general/76997
http://thread.gmane.org/gmane.comp.gnu.lilypond.general/16000
didn't help me so much. (There is a hint, but I think, its bad, if I must solve 
everything for R manually while r works fine.)

Any ideas to solve that?

Werner