MSCIM does not have a virtual keyboard. It replaces N900's native input altogether. It's not missing. It's expected. So other than some apps (such as Swappolube) hard coded to use the native input which enables VKB, you will not see the VKB on any other apps as it does not exist with MSCIM. (Opera Mobile is another example but this time, it has its own virtual keyboard and doesn't rely on the native VKB altogether)