The stick separates apparently after a while without traffic the connection itself (estimated after a few hours) and these can then be apparently no longer wakes from IPFire. Here helped a reboot, but may also reaches a neueinstecken the stick.
Ansich I am very satisfied, the score for the (unmeasured, but according to data sheet) low maximum bandwidth and no longer recoverable automatic idle-separation. Also, the Web Interface on 192.168.1.1 do not like very, since the settings are restricted and can not be password-protected access to it (eg for potential malware).
Had to stick well to a Fritz! Box (7270) with the latest firmware out of the box where he was also recognized and worked.