what pix IOS version are you running? 6.3+ has sccp and mgcp support, just to name some of the added features. perhaps you should consider an upgrade to 6.3+ before you implement your ccm voip through it.
also, rtp traffic would be sent between phones only after all call setup, etc. has completed. since the pix is between the two endpoints, you'll need to allow for the udp rtp streams created in both directions for a single call.
also, should create, or if you're running 6.3+, enable the fixup for mgcp. (sccp is enabled by default 6.3+)
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.