What computer operating system is your Premiere Elements 12 running on? For now I will assume Windows 7, 8, or 8.1 64 bit in case I need to mention specifics.
What you describe is probably a mismatch of project settings importing and exports. So let us start with details.
What have you or the project set automatically for the project preset? (See Edit Menu/Project Settings/General and the readings for Editing Mode, Timebase, Frame Size, and Pixel Aspect Ratio even if they appear to be grayed out.)
What are the properties of what you are putting on the project's Timeline? Do the properties of the source media match the details of the project preset that you are using.
Then the most likely cause of the problem...your export settings.
From what you wrote, you are probably using
Now the important part, what are you selecting for "Presets" and what are your settings under the Advanced Button/Video Tab and Audio Tab of the preset selected?
The answers will be in your details.
If you have questions about what is written or need clarification on it, please do not hesitate to ask. But, the answers are need for all of the above.
Thank you for the prompt reply. It seems as though I have the situation figured out now. I checked the project settings as you stated and that enlightened me on the whole issue. I guess I never gave it much that the presets had to be the same as to what you finalize the project in. My preset was 720x480 and I was save the project down something larger - I suppose this was the problem for future reference?
Once again, thank you for your help. I am new to video editing and trying to learn this as I go, so any help is much appreciated!
Thanks for the follow up. It sounds like you have everything under control. Good job.
But, if any problems still exist and you need suggested project settings and export settings, please do not hesitate to ask and post the details.