Mac 0S 10.5.4 and 7.4.2 install problems

Yesterday I purchased an 003 rack that came with ProTools LE 7.3. I read up well prior to installing and installed a clean version of 7.4.2 installer from my newly created "my digi" online acccount. The installer runs smoothly until the end. At the end it reads, "Installation Failed. Installer could not install some files in the "/." If I hit restart a few more warnings come up telling me that a few digidesign items do not have proper security settings (digidesign loader, etc). If I try to open a session, a warning window tells me there is "no audio volume." If I open workspace I see no volumes and the message "You don't have appropriate access." I've - confirmed my adminstrator settings - tried repairing the security settings and also fixing permissions in the disc utility app. - tried to install either my imac or macbook pro with no success (both running 10.5.4). The installer continues to manifest the same issue. I feel like I must be missing something - any thoughts? I tried calling Customer Service all day however they must be shutdown as it played an incorrect announcement about vacation on Presidents Day in Feb! Ha! Someone help the newbie! : )

Here are either computer specs - iMac 24" 2.4ghz IntelCore Duo, 4GB Ram, 300Gb. OSX.5.4 - Macbook 2.4ghz Intel Core Duo, 2GB Ram, 150GB. OSX.5.4

I was fairly certain 7.4.2 only supports up to mac os x 10.5.3 at this point? I remember reading some people were having issues once they made the upgrade to 10.5.4.

Thank you for your post. Install problems similarlly manifested on a 10.5.3 machine. Not to negate your thoughts, however, many posts I read had users happily using the newest LE OS alongside 10.5.4. I also am aware of this . I think it's something else. Like maybe my drive?? One set of instructions said to open disc utility and click "journal" however I can't find that option. I can read at the bottom that it's format is OSX extended (journaled). Hmmm

Try installing PT in stages. 1. Clean uninstall PT using the utility in the 7.4.2 installer 2. Delete preferences and databases (detailed instructions in the troubleshooting thread above). 3. Empty trash and reboot. 4. Run the 7.4.2 installer but uncheck everything except the PT application (no plug-ins etc). 5. Reboot and run the installer again but this time uncheck PT and check plug-ins.

Thank you for those suggestions. I followed all the steps you suggested. In addition, I re-confirmed and downloaded 7.4.2 installer as well. Finally, I removed all of Adobe Creative Suite as there were some issues with it and Leopard way back when. Something in the entire process fixed everything. It's fixed! Andy