Installer runs painfully slow when running off a cd.

I have written an installer that copies directories from a cd to the machines file system, and calls another utility of ours that does some sql operations.

Running the installer from the root of the cd causes it to hang during a RMDIR command, and the installer takes about twice as long to complete than if I copy it to the target machine and run it from there. At the end of the install, the installer does a RMDIR /r on a temporary directory, and I can see it delete the files in the detail window, but when it tries to remove the folder, it takes forever, somewhere upwards of 10 minutes.

I have watched the installer in task manager and during this time it uses almost no processor.

Has anyone else had this issue, or know why this might be the case?

If it's not already the case:
Before RMDIR, try to SetOutPath to a directory different than the one you're trying to delete. This might explain why the installer has a hard time deleting the folder itself.