[ESS] R window: Text is read only

[Christian]

Hi, after start with M-x R the R window behaves OK, allowing writing to. 
BUT, after navigating in the help system, R refuses writing with "Text 
is read only". This makes R unusable. I found no help on the net, so, 
please, give me some hints.
This behaviour started bothering me out of the blue. Some mis-manipulation?

TIA  C.
-- 
Christian Hoffmann
Rigiblickstrasse 15b
CH-8915 Hausen am Albis
Switzerland
Telefon +41-(0)44-7640853