I'm not sure if your current running configuration is the same as you posted a couple of weeks ago but you should be able to see what is needed for this to work. You will have to implement the following configuration changes based on your last posting of the running config.
Please read the changes carefully as it contains a part that requires input from you (backup ISP device IP address to monitor).
Interesting items to point out so far:
1. Interface Fa1 seems to be administratively shutdown.
2. ip sla 2 is missing entirely from the config.
3. ip sla 1 doesn't specify source interface as Fa0.
4. there is no ACL on interface Fa1 which is going to be needed if it is used as backup interface.
5. there are no NAT statements for when interface Fa1 is going to be used. You can use a DynDNS.org client to update a DNS name to make it easier for you to know what IP address the backup interface is using.
6. you mentioned load balancing outbound web traffic. you will have per destination load balancing outbound if you have fast-switching enabled on the interfaces which i think you already do have.
give this a try and let us know the outcome.
!
access-list 102 permit udp any eq domain any
access-list 102 permit udp host 132.163.4.102 eq ntp any
access-list 102 permit tcp any any eq 1494
access-list 102 permit tcp any any eq 5367
access-list 102 permit tcp any any eq 5366
access-list 102 permit tcp any any eq 5365
access-list 102 permit tcp any any eq 5364
access-list 102 permit tcp any any eq 3389
access-list 102 permit tcp any any eq 5360
access-list 102 permit tcp any any eq 5361
access-list 102 permit tcp any any eq 5362
access-list 102 permit tcp any any eq 443
access-list 102 permit tcp any any eq www
access-list 102 permit tcp any any eq smtp
access-list 102 permit icmp any any echo-reply
access-list 102 permit icmp any any time-exceeded
access-list 102 permit icmp any any unreachable
!
interface FastEthernet1
ip access-group 102 in
no shutdown
!
no ip route 0.0.0.0 0.0.0.0 FastEthernet1 20
!
do clear ip nat trans force
no ip nat inside source list 1 interface FastEthernet0 overload
no ip nat inside source route-map backup-nat interface FastEthernet1 overload oer
no ip nat inside source route-map primary-nat interface FastEthernet0 overload oer
!
ip nat inside source static tcp 10.2.1.4 1494 interface FastEthernet1 1494 extendable
ip nat inside source static tcp 10.2.1.4 3389 interface FastEthernet1 3389 extendable
ip nat inside source static tcp 10.2.1.2 5360 interface FastEthernet1 5360 extendable
ip nat inside source static tcp 10.2.1.3 5361 interface FastEthernet1 5361 extendable
ip nat inside source static tcp 10.2.1.74 5364 interface FastEthernet1 5364 extendable
ip nat inside source static tcp 10.2.1.77 5365 interface FastEthernet1 5365 extendable
ip nat inside source static tcp 10.2.1.78 5366 interface FastEthernet1 5366 extendable
ip nat inside source static tcp 10.2.1.100 5367 interface FastEthernet1 5367 extendable
ip nat inside source static tcp 10.2.1.6 25 interface FastEthernet1 25 extendable
ip nat inside source static tcp 10.2.1.6 80 interface FastEthernet1 80 extendable
ip nat inside source static tcp 10.2.1.6 443 interface FastEthernet1 443 extendable
ip nat inside source static tcp 10.2.1.6 5362 interface FastEthernet1 5362 extendable
!
ip nat inside source list 1 interface FastEthernet1 overload
ip nat inside source list 1 interface FastEthernet0 overload
!
no track 123
!
no track 345
!
no ip sla 1
!
ip sla 1
icmp-echo 216.203.117.81 source-interface FastEthernet0
frequency 5
!
ip sla schedule 1 life forever start-time now
!
ip sla 2
icmp-echo X.X.X.X source-interface FastEthernet1 (needs to be an IP address on backup ISP network)
frequency 5
!
ip sla schedule 2 life forever start-time now
!
track 123 rtr 1 reachability
delay down 10 up 5
!
track 345 rtr 2 reachability
delay down 10 up 5
!
no route-map primary-nat
!
no route-map backup-nat
!
