Apologies butting in here with something slightly OT as far as Mikrotik is concerned.

Using your setup are you able to run a command similar to "show ip route" ?

Does the network operator provide you with one public IP with which to NAT your subnet ?
What does you routing table look like ?

This is what I get using ADSL

Code:
Gateway of last resort is 0.0.0.0 to network 0.0.0.0

C    192.168.30.0/24 is directly connected, Vlan6
C    192.168.10.0/24 is directly connected, Vlan2
C    192.168.20.0/24 is directly connected, Vlan4
     41.0.0.0/32 is subnetted, 4 subnets
C       41.185.170.1 is directly connected, Dialer1
C       41.146.12.231 is directly connected, Dialer2
C       41.185.170.76 is directly connected, Dialer1
C       41.146.0.1 is directly connected, Dialer2
S*   0.0.0.0/0 is directly connected, Dialer1
               is directly connected, Dialer2
This is what I get using Cellular

Code:
Gateway of last resort is 0.0.0.0 to network 0.0.0.0

S*    0.0.0.0/0 is directly connected, Cellular0/1/0
      41.0.0.0/32 is subnetted, 1 subnets
C        41.12.176.157 is directly connected, Cellular0/1/0
      192.168.40.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.40.0/24 is directly connected, FastEthernet0/0
L        192.168.40.3/32 is directly connected, FastEthernet0/0
It would appear to me that the provider IP should be similar to the ADSL and be subnetted into two subnets
I can ping out from the router but not from the PC ( same subnet different IP )
I am also not getting any NAT taking place.

I am trying to work out if I have screwed something else up or if the problem is elsewhere ?

I am just wondering if the SIM card has to be provisioned in some way or if I need to use another APN ? ( using the standard "INTERNET" As you can see from the IP -- Vodacom )

Sorry for the OT but I am pretty sure you can help.

Please let me know if I need to post this somewhere else

Thanks