Here are some more details. - Working on a Debian 64-bit install, - Stock debian kernel, v3.1.5 - official jack2 v.1.9.7 64-bit packages from Debian, - Jack works properly with native 64-bit applications, like audicious. - Specifically testes Pianoteq 64-bit with jack, and it works OK - manually installed 32-bit jack2 libs (from Debian i386) - When trying to run pianoteq 32-bit, I get this: ---------------------------- Jack error: Cannot lock down 68157440 byte memory area (Cannot allocate memory) Jack error: Cannot lock down 4196401152 byte memory area (Cannot allocate memory ) Jack error: Cannot lock down 25165824 byte memory area (Cannot allocate memory) Jack error: You cannot set callbacks on an active client Jack error: You cannot set callbacks on an active client Jack error: You cannot set callbacks on an active client Jack error: You cannot set callbacks on an active client Jack error: You cannot set callbacks on an active client Segmentation fault *********************** I was seeing similar error messages with fst and wineasio - both linked to the 32-bit jack library, but since they also both involve WINE, they are harder to debug, this is I involved Pianoteq in the testing; it's a native linux app, available in both 32-bit and 64-bit version. * * * So, it looks like my hybrid 64-bit / 32-bit jack installation is dysfunctional. That's why I am asking this: is this (32-bit jack clients connecting to a 64-bit deamon) even supposed to work? Thank you: Kristof 2011-12-18 23:15 keltezéssel, Csillag Kristof írta: