It is a bit disappointing, and odd because one of the main changes to the 2.4 branch was better icarus detection.
So maybe it's a bit ironic that it detects icarus better, but BFL not at all anymore
The change was simply to detect Icarus before BFL rather than BFL before Icarus.
(since it was reported that BFL detection was messing up Icarus and that was the ... ... that someone else supplied ...)
Anyway, with the names added to the front, there should be no difference at all between the detection in 2.3.6 and 2.4.1 since the names (another ... ... that someone else did quite a while back) would force the devices to never even be looked at by the other driver
i.e. with a name like bitforce:\\.\COM10 - the Icarus detection would never touch the \\.\COM10 port before the Bitforce detection gets a look at it.
Hmm - maybe I should actually force that rather than let the code work the way it was implemented.
i.e. there is likely be some other problem ... and ckolivas suggestion to try this with a single BFL on your rig is probably the best chance at sorting it out
Remember you can run your rig with 2.3.6 using all but one BFL and then run testing on the last BFL with 2.4.1 at the same time (and switch that one between 2.3.6 and 2.4.1 as needed)
Anyway, if you get a chance come back and visit #cgminer again and if I'm around and have time then I'll see if we can resolve it with a single BFL
(P.S. the translation of '... ...' is 'hack' )