Custom Apps Installing but not there

I have several custom Applications being installed, and some of them do not actually appear on the system. only 2 apps are having this issue, firefox and thunderbird, which were working fine, until i upgraded to 1.4b1 I see in the instadmg logs that that all applications appear to install properly. I have receipts saying the install happened, yet Firefox and Thunderbird are nowhere to be found on the disk. if i grab those pkgs and install them again on the system they work just fine. Any ideas? I have seen some problems when packaging with leopard packagemaker where the install decides to divert the files to a different location. if i make the same pkg in tiger packagemaker then it never happens. but i cannot see the diverting messages in the instadmg logs. thanks.