Look to this on my website, in dutch but folow the print screens a made.
This is a Groove function as router
http://www.wirelessinfo.be/index.php/mi ... s/grooveap

What antenna on the Groove?

It can be your signal is to strong.

You must reduce the output power.

Try with laptop and inssider to look to the signal let me know how match the signal is.

http://www.inssider.com/downloads/

Standing the Groove inside or outside?

Can you post an export from your configuration?

Log in with winbox and click on the main window on "new terminal" type "export"
copy and paste this code to this forum.
Caution hide sensitive data like password

/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
add authentication-types=wpa-psk,wpa2-psk eap-methods="" \
    management-protection=allowed mode=dynamic-keys name=Passwd_profile \
    supplicant-identity="" wpa-pre-shared-key=123456789 wpa2-pre-shared-key=\
    123456789
add authentication-types=wpa-psk,wpa2-psk eap-methods="" \
    management-protection=allowed name=FREE supplicant-identity=""
/interface wireless
set [ find default-name=wlan1 ] antenna-gain=15 band=2ghz-b/g country=\
    pakistan disabled=no frequency=2422 mode=ap-bridge security-profile=\
    Passwd_profile ssid=MyNet4G

You have measured the signal with inssider?I
I would first like to see the result.
Measures at the place where you can connect.
Also measures where you can't connect.
So better look for a solution.

You have measured the signal with inssider?I
I would first like to see the result.
Measures at the place where you can connect.
Also measures where you can't connect.
So better look for a solution.

This signals are good.

How high is the groove installed?

Set by wireless the protocol on 802.b,g,n