Mine would do it cold or warm, wet or dry!!
Just as a footnote to johngg's experience, mine was done recently by Newport so they are aware of the "fix". Having said that, the first time I took it there and left the car with them, they couldn't find a fault...
Current - M-Benz C250Cdi Sport Plus Auto Est.
Previous - Alpina D3 BiTurbo E90 LCI Manual, 320d M Sport E92 Auto, 330i M Sport E92 courtesy of BMW UK....320i M Sport E92 Auto, 320d SE E90 Manual.