I have a very similar issue. I get the following behaviour:
kernel 2.6.15-23-amd64-k8: nm-applet works as it should (modulo some minor annoyances)
any later kernel: nm-applet never appears in the tray. If I kill it and restart it, I see the other tray icons move around a bit, but the nm-applet icon never appears.
I'm using the bcm43xx driver, maybe this behaviour is related to some changes in the driver between kernel versions?
I have a very similar issue. I get the following behaviour:
kernel 2.6.15-23-amd64-k8: nm-applet works as it should (modulo some minor annoyances)
any later kernel: nm-applet never appears in the tray. If I kill it and restart it, I see the other tray icons move around a bit, but the nm-applet icon never appears.
I'm using the bcm43xx driver, maybe this behaviour is related to some changes in the driver between kernel versions?