Are you working with the 8.0.1 Update (Patch) version of Premiere Elements 8? If so, the automatic Background Rendering feature is then turned OFF as the default for that. Background Rendering and the AutoAnalyzer features should be turned OFF in Premiere Elements 8 because they are major grabbers of system resources. Use then on the on demand basis only...instead of the automatic Background Rendering, use, when and if needed, the rendering of the Timeline by pressing the Enter Key of the computer main keyboard. For AutoAnalzyer, right click the Organize thumbnail and select Run AutoAnalzyer when and if needed.
When you render a Timeline in Premiere Elements 8.0/8.0.1 (red line over Timeline to green), preview files are automatically generated and stored in the Adobe Premiere Elements Preview Files Folder on the hard drive (.avi files for SD and .mpg files for HD). After you save/close/re-open your project with the previous "rendered" Timeline, you may or may not now find a red line over that content which would seem to be the program telling you that Timeline content under it needs to be rendered to get the best possible preview. In the cases where there is now a red line, the preview files ARE STILL THERE in the Adobe Premiere Elements Preview Files Folder. They have not been removed. If you know that the content was OK first time around, I would say "Move On." And, if you have to render the Timeline for additional content, then use the WorkArea Bar tabs to render selectively this additional content.
Please let me know if you need clarification on anything that I have written here. This type of question has been asked over and over again for Premiere Elements 8, and many have found that the approach cited works for them.
Did you mean Premiere Elements 8?
The only way that I have heard about Premiere Elements 7 solving the Premiere Elements 8 render business that was asked about was to use Premiere Elements 7 for the video editor instead of Premiere Elements 8. This is the first that I have heard about QuickTime being involved in the rendering indicator issue of Premiere Elements 8.
You can find the 8.0.1 link and article to determine if you have it or not* here: All the links for PRE 9, 8 and 7
* The 8.0.1 patch does not, unfortunately, update the Help> About
Insanity is hereditary, you get it from your children
That 8.0.1 Update (Patch) can be downloaded and installed via
a. Help Menu/Update
b. A download from Adobe
where the Download Information includes
"NOTE: This update will not change the version number displayed in the Premiere Elements Splash Screen or About Box. After the update has been installed the version will continue to read "8.0"."
I am not sure why Adobe opted to do it that way.
Many have asked "Then how do I tell if I have the 8.0.1 installed?"
a. When you downloaded and installed the Update, you should have gotten a message saying that the Update was successfully installed.
b. Before the installation, the automatic Background Rendering is set for the default of ON. Once the Update is installed, the automatic Background Rendering (Edit Menu/Preferences/General) is turned OFF.
c. If you look to the Premiere Elements program files, you will now find a DisplayDrivers.dll with an earlier date than the rest of the files in that area.
d. You try to install it, and you get a message that you do not need updates.
The composite of the above is not the cleanest way to answer the question, but... Typically, the first thing that you notice after the 8.0.1 Update is installed is a marked improvement in every aspect of the program's performance bringing it up to par with previous versions.