Yes that module is listed as compatible with the switch. Sounds like you are installing in bay 2? It  may have listed those ports but they probably did not show up as enabled. Have you tried making a connection with the ports? 
Hello, We recently installed a SFP+ module (part # c107d) in to our Dell PowerConnect 6248 switch. The switch does not appear to be seeing the module because prior to us installing the module it showed an xg3 and xg4 port, and after adding the module it still only shows those ports. So I have a few questions: Is the SFP+ mentioned above compatible with this model of switch? If  so, how can we verify the ports are active?  Here is the output of the port details:  #show interfaces detail ethernet 1/xg3   Port   Type                            Duplex  Speed    Neg   Admin  Link                                                               State  State -----  ------------------------------  ------  -------  ----  -----  ----- 1/xg3  10G - Level                     N/A     Unknown  Auto  Up     Down     Port  Description ----  -------------------------------------------------------------------------- 1/xg3   Flow Control:Enabled Port: 1/xg3 VLAN Membership mode:Access Mode   Operating parameters: PVID: 1 Ingress Filtering: Enabled Acceptable Frame Type: Untagged Default Priority: 0 GVRP status:Disabled Protected:Disabled   --More-- or (q)uit Port 1/xg3 is member in:   VLAN    Name                              Egress rule   Type ----    --------------------------------- -----------   -------- 1       Default                           Untagged      Default   Static configuration: PVID: 1 Ingress Filtering: Enabled Acceptable Frame Type: Untagged   Port 1/xg3 is statically configured to:   VLAN    Name                              Egress rule ----    --------------------------------- -----------   Forbidden VLANS: VLAN    Name ----    ---------------------------------     Port 1/xg3   Enabled State: Disabled                                  Role: Disabled --More-- or (q)uit Port id: 128.51                                  Port Cost: 0 Port Fast:  No (Configured: no )                 Root Protection: No Designated bridge Priority: 32768                Address: 80:00:00:25:64:19:92:1C Designated port id:   0.0                        Designated path cost: 0 CST Regional Root: 80:00:00:25:64:19:92:1C       CST Port Cost: 0 BPDU: sent 0, received 0 
Dell PowerConnect 6248 10 GB ports not working