Do you mean you have (m)scim and google pinyin installed? If yes you have mscim then you will never see virtual kb. mscim will take over the input interface from the default hildon input method. This is explicitly stated by the maintainer and you can only have either one not both.

If you have scim installed instead, good luck.... I installed scim and something else earlier and it ruined my virtual kb. The vkb became an empty box with only the minimize button. I tried many things but end up re-flashing my phone to bring back virtual kb.