On Sat, 16 May 2015, Brian wrote:
A comparison of the outputs from 'apt-config dump' on both laptops might give something.
  alas no!
  after copying the /etc/apt directory from laptop2 to my laptop, the only difference is
  ==> diff apt-config_dump.ch8 apt-config_dump.mynb
      132c132
      < Acquire::Languages:: "fr";
      ---
      > Acquire::Languages:: "en";
      133a134
      > Acquire::Languages:: "fr";
   	 I don't think it can explain the problem.
   	 I'm rather reluctant to do a bug report, as I'm the only one to
   	 have this issue, and will probably use one of the proposed workarounds,
   	 although it's frustating to leave this mystery unexplained.
Unreproducible here on a new bare-bones i386 Wheezy install with the same mirror.
for me too, on my i386 desktop, wheezy or jessie. best regards, -- Pierre Frenkiel