I made a copy of portal default framework page and made some changes in the copy. Later when I transport all content from dev to QA, I export the customized framework page to a transport package, but somehow it didn't get uploaded and imported in QA. So my question is: is it possible to export and import customized framework page from one box to the other? I searched around help docs and forums, didn't find a certain answer.
Try to debug the issue by opening the transport epa on source system and check if your framework page is included there. As EPA file is just a zip file, you can open it with and zip utility and check file PACKAGE-INF/package.xml for your framework page, if it is there then you have it in EPA.
If page is in epa then the problem could be on epa import, so check logs on destination server to know more during importing.