Are pre-releases portable applications or normal applications?

the pre-releases are portable as well

The testing process here goes:

Development Test - Pre-Release - Official Release

The app is still portable just in the process of testing. At Pre-Release stage they are usually high grade though not always.

hope this helps

Perhaps it would help if you said a bit more about what you mean by "install a normal application". Have you seen regular PortableApps PAF installers? They do look a lot like normal application installers, especially if you are not installing from the PortableApps menu.

Are you sure you were using a PortableApplication installer? If it was, the filename ends in .paf.exe (some or all of which may be hidden by your operating system for your convenience and entertainment). Perhaps you were actually installing the "real" application instead of the portablized version?

It's also possible you stumbled on a bug that needs to be fixed before it moves from pre-release to release. So the direct answer to your question is, yes, it should behave in a portablized fashion, and if you are sure you were running the PAF version of the installer, it should clearly identify itself as installing the PortableApps version. If it still isn't working for you, go to the topic in the Beta forums for that portable app and report what you saw and did (in great and boring detail).