Lack of IP Connectivity

Hi

Can any one please help identify the issue in scenario 2:

Connectivity Diagram:
1) Distribution Switch----Int_Switch----LabSwitch(Fa1/0)----Terminal Ser
2) Distribution Swtich----Int_Swtich----LabSwitch(Fa2/0)----3640 Router

---all links are access links

Distribution Switch (int vlan 10 = 10.1.96.251/26)
Int_Switch (int vlan 10 = 10.1.96.196/26)
LabSwitch (int vlan 10 = 10.1.96.234/26)
Termial Ser (Int Eth0 = 10.1.96.254/26)
3640 Router (int Fa1/0 = 10.1.96.245/26)

Scenario1: I could able to successfully ping/telent Termianal server from my pc.

Scenario2: Can able to ping Distribution switch ip from 3640 router and vice versa. But cannot able to ping/telnet from my pc. I have also confiured a default router on router as 0.0.0.0 0.0.0.0 10.1.96.251 but still cannot able to ping. i have a default-gate 10.1.96.251 configured.

Can any one please help in scenario2, if I am missing some thing.

Thanks in advance.