How to restart hostapd correctly

[Jar]

Hello

I am currently using hostapd-0.6.9 with prism 2.5 card. When I changed 
the line 'wpa_pairwise=CCMP' to 'wpa_pairwise=CCMP TKIP' in the 
hostapd.conf and then kill hostapd and start it again neither WPA/TKIP 
nor WPA2/AES clients can connect. But if I reboot the whole PC all 
clients can connect perfectly.

My question is, how to re-start hostapd daemon correctly so that it 
reads the changed .conf file so that clients could connect after that 
change without rebooting.

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Best Regards, Jar