Sometimes when i close Konsole i feel that my CPU goes a bit mad, then when i go to task manager, i can see that the process of konsole it's still running and using the CPU

you can check it this two screenshots (there is few konsoles "opened" but when you see the other screenshot you can check that there is no konsole opened)

http://i.imgur.com/MrxG8be.png
http://i.imgur.com/kgc4JzD.jpg

Reproducible: Sometimes

Steps to Reproduce:
1. Open Konsole
2. Do something
3. Close konsole
4. Open Task Manager
5. See that there is a Running Konsole using the CPU

Actual Results:  
Konsole it's still running and eating my cpu

Expected Results:  
Konsole should not running

x11tete11x@Jarvis:~$ inxi -Fx
System:    Host: Jarvis Kernel: 3.19.0-15-generic x86_64 (64 bit gcc: 4.9.2)
           Desktop: KDE 5 Distro: Ubuntu 15.04 vivid
Machine:   System: Sony product: VPCF236FM v: C609S2A8
           Mobo: Sony model: VAIO
           Bios: American Megatrends v: R2150V3 date: 07/22/2011
CPU:       Quad core Intel Core i7-2670QM (-HT-MCP-) cache: 6144 KB
           flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 17558
           clock speeds: max: 3100 MHz 1: 2800 MHz 2: 2799 MHz 3: 2799 MHz
           4: 2799 MHz 5: 2799 MHz 6: 2799 MHz 7: 2799 MHz 8: 2799 MHz
Graphics:  Card: NVIDIA GF108M [GeForce GT 540M] bus-ID: 01:00.0
           Display Server: X.Org 1.17.1 drivers: nvidia (unloaded: fbdev,vesa,nouveau)
           Resolution: 1920x1080@59.9hz
           GLX Renderer: GeForce GT 540M/PCIe/SSE2
           GLX Version: 4.5.0 NVIDIA 346.59 Direct Rendering: Yes
Audio:     Card-1 NVIDIA GF108 High Definition Audio Controller
           driver: snd_hda_intel bus-ID: 01:00.1
           Card-2 Intel 6 Series/C200 Series Family High Definition Audio Controller
           driver: snd_hda_intel bus-ID: 00:1b.0
           Sound: Advanced Linux Sound Architecture v: k3.19.0-15-generic
Network:   Card-1: Intel Centrino Wireless-N + WiMAX 6150
           driver: iwlwifi v: in-tree: bus-ID: 02:00.0
           IF: wlan0 state: up mac: 40:25:c2:7b:d3:6c
           Card-2: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
           driver: r8169 v: 2.3LK-NAPI port: 9000 bus-ID: 05:00.0
           IF: eth0 state: down mac: f0:bf:97:da:2a:1c
Drives:    HDD Total Size: 750.2GB (1.6% used)
           ID-1: /dev/sda model: TOSHIBA_MK7559GS size: 750.2GB
Partition: ID-1: / size: 39G used: 6.0G (16%) fs: xfs dev: /dev/sda5
           ID-2: /boot size: 475M used: 49M (11%) fs: ext4 dev: /dev/sda3
           ID-3: /home size: 299G used: 4.4G (2%) fs: xfs dev: /dev/sda7
           ID-4: swap-1 size: 1.02GB used: 0.00GB (0%) fs: swap dev: /dev/sda6
RAID:      No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors:   System Temperatures: cpu: 81.0C mobo: N/A gpu: 0.0:60C
           Fan Speeds (in rpm): cpu: N/A
Info:      Processes: 297 Uptime: 2:56 Memory: 4164.6/7964.4MB
           Init: systemd runlevel: 5 Gcc sys: 4.9.2
           Client: Shell (bash 4.3.301) inxi: 2.2.16



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i am using Kubuntu backports with Plasma 5.3 (BTW i tested on Kubuntu Plasma 5.2 and still happens)

Plasma: 5.3
KF: 5.9.0