I have tried to install Fuse IDE on the RCP and the JEE versions of Eclipse Helios and both were working fine. Could you tell us more about your used Eclipse version? Any chance that you are using Spring STS or installed it from their update site?
For the moment Fuse IDE is not compatible with Spring STS and therefor this could be a reason why you don't see the perspective.
Please let us know about your Eclipse installation details.