Jan
The info is pretty straight forward.
According to Agfa Technical data sheet C-SW56-E17, 06/04 (17th edition) the times for Rodinal 1:50 for a gamma of 0.65 (considered normal contrast) the times are:
1:25 12 mins
1:50 20 mins
the times you stated are for the lower gamma of 0.55 for the 2003 on emulsion, also you may like to note some Agfa literature uses the 1:50 for 30 mins that's not really insane at all but par for the course for the earlier emulsions.
Chris I have the Agfa data sheets for 1990's published in the pamphlet 'Action, Emotion, Memories'
The B&W manual of Agfa Products.
They clearly state on page 29:
Film speed at gamma 0.65
APX 400 1:25 15min ISO 320/26°
APX 400 1:50 30min ISO 400/27°
I have found a PDF version here:
http://www.silverprint.co.uk/pdf/agfa_bw_manual.pdf
I can categorically state that the times are correct for the old emulsions, developing to your times with the pre '03 emulsions would give lower contrast say 0.55 gamma or lower.
I think people here are conflating two issues, the change of emulsion (early 2000's) and the lower gamma.