This issue is discussed in this thread:
Currently the karaf feature feature installs bundles in this sequence - Install/Start/Install/Start/Install/Start. The problem with this sequence is that if the following bundles are installed late:
+ bundles which are optional imports of other bundles and/or
+ bundle fragments
some bundles may not resolve with their optional imports and fragments.
The solution is to install bundles in the following sequence - Install/Install/Install/Install...Start/Start/Start/Start. In that way all bundles are installed before any bundles are started and thus all optional imports and fragments should get resolved.