strange reset phenomenon

[hyla]

Hi, everybody.

Strange thing here: I've got a MySensors sensor here (some variety of a teperature-humidity sensor).
Gateway I'm using is the ethernet version. Whenever I reset my sensor the ethernet gateway resets too:

2016-02-27 10:14:12.664 MySensors: Connection reset!
2016-02-27 10:14:12.665 TCP: Reconnecting in 30 seconds...
2016-02-27 10:14:37.607 Hardware Monitor: Fetching data (System sensors)
2016-02-27 10:14:42.669 TCP: Reconnecting...
2016-02-27 10:14:42.669 MySensors: connected to: 192.168.2.155:5003
2016-02-27 10:14:43.670 MySensors: Gateway Ready...
2016-02-27 10:14:43.670 MySensors: Gateway Version: 1.5.1
2016-02-27 10:14:44.672 MySensors: Gateway Version: 1.5.1

Each and every time.

In the WireShark protocol this is reported:

27 20.628064000 8 0 mysensors 20 Cmd:PRESENTATION, ReqAck:0, IsAck:0, Type:ARDUINO_NODE, Sns:255, Data:'1.5' [STRING]
28 20.635184000 8 0 mysensors 18 Cmd:INTERNAL, ReqAck:0, IsAck:0, Type:CONFIG, Sns:255, Data:0 [BYTE]
29 21.662740000 0 8 mysensors 18 Cmd:INTERNAL, ReqAck:0, IsAck:0, Type:CONFIG, Sns:255, Data:'M' [STRING]
33 22.656000000 8 0 mysensors 25 Cmd:INTERNAL, ReqAck:0, IsAck:0, Type:SKETCH_NAME, Sns:255, Data:'Humidity' [STRING]
34 22.658412000 8 0 mysensors 25 Cmd:INTERNAL, ReqAck:0, IsAck:0, Type:SKETCH_NAME, Sns:255, Data:'Humidity' [STRING]
35 22.666184000 8 0 mysensors 21 Cmd:INTERNAL, ReqAck:0, IsAck:0, Type:SKETCH_VERSION, Sns:255, Data:'1.02' [STRING]
36 22.673444000 8 0 mysensors 17 Cmd:PRESENTATION, ReqAck:0, IsAck:0, Type:HUM, Sns:0
37 22.675600000 8 0 mysensors 17 Cmd:PRESENTATION, ReqAck:0, IsAck:0, Type:HUM, Sns:0
38 22.682072000 8 0 mysensors 17 Cmd:PRESENTATION, ReqAck:0, IsAck:0, Type:TEMP, Sns:1
39 22.684236000 8 0 mysensors 17 Cmd:PRESENTATION, ReqAck:0, IsAck:0, Type:TEMP, Sns:1
40 24.701744000 8 0 mysensors 22 Cmd:SET, ReqAck:0, IsAck:0, Type:TEMP, Sns:1, Data:1102105856,000000 [FLOAT32]
41 24.709544000 8 0 mysensors 22 Cmd:SET, ReqAck:0, IsAck:0, Type:HUM, Sns:0, Data:1109970176,000000 [FLOAT32]

So the gateway seems to answer once (29) and then it resets. So far this type of sensor is the only one who does this.
I've do have another practically identical sensor who has the same effect. Both have worked before.
Although I might have changed something inbetween. Other sensors work flawlessly...
Electrically sensor and gateway are completely separated (sensor driven on a battery, gateway feeds on a 2A wall wart).
The sensor is not detected (anymore).

Any ideas?

Curious thing, thanks for any input,

Christoph

[edit: I'll probably cross-post that on Mysensors forum as well, seems to make sense]