We are planning to install Call Manager Express on our Cisco 3845 router. However, I do not know which version to install and which IOS. I tried to check the Cisco IOS and CME Compatibility Matrix page and saw that version 4.1 is the recommended version and it is supported starting 12.4(15)T7 IOS. I already downloaded CME 4.1 but I can't choose which IOS to install. I'm trying to download 12.4(15)T7 but Cisco warned me that it has a problem (you know when Cisco warns you whenever you are downloading a broken IOS). So I planned to choose other version but I'm having a hard time choosing which IOS will fit both IOS and CME on a 128MB flashcard. I am now downloading 12.4(11)XW7 IP Voice but I'm not 100% sure if CME 4.1 will work on this platform. Can anyone help me choose the right IOS? Thanks.