When you say "sdm files", I think you are meaning the .tar files, correct?
Also, "ip http secure-server" isn't the only thing you need to configre SDM. I'm having a bit of a problem myself. I was able to finally get my SDM to connect to a virtual router in GNS3 environment. However, I now have a 2620XM myself, and SDM won't connect. But, you need to ensure you have aaa new-model running, you need authentication setup for a local user, you need your interfaces properly addressed. I'm going to be posting my own issue with SDM, but here is the config I used:
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R1
!
boot-start-marker
boot-end-marker
!
logging buffered 51200 warnings
logging monitor informational
!
memory-size iomem 10
no network-clock-participate slot 1
no network-clock-participate wic 0
aaa new-model
!
!
aaa authentication login AAA_LIST_NAME local
aaa session-id common
ip subnet-zero
ip cef
!
username yallaen privilege 15 secret 5 $1$P1rJ$oVvrGIy3m.zjxFspdIP.B1
!
interface Loopback0
ip address 192.168.1.2 255.255.255.0
!
interface FastEthernet0/0
description Network 10.0.0.0/30
ip address 10.0.0.1 255.255.255.252
duplex auto
speed auto
!
interface FastEthernet0/1
description Network 192.168.1.0/24
no ip address
shutdown
duplex auto
speed auto
!
router eigrp 1
network 10.0.0.0 0.0.0.3
network 192.168.1.0
auto-summary
!
ip http server
ip http authentication local
ip http secure-server
ip http timeout-policy idle 600 life 86400 requests 10000
ip classless
!
!
logging history size 300
logging history informational
logging facility local6
!
!
line con 0
privilege level 15
logging synchronous
login authentication AAA_LIST_NAME
line aux 0
line vty 0 4
privilege level 15
login authentication AAA_LIST_NAME
transport input telnet ssh
line vty 5 15
privilege level 15
login authentication AAA_LIST_NAME
!
!
end
