Trouble Uploading Images

Hey everyone,
quick info about myself: I am in my second year of Multimedia Production in college and for my practicum I am creating a website using Omeka.

Alright, now my problem is I am trying o add items with images an it doesn't seem to want to work. On Monday I could at least get it to say that the item was added successfully, but the image wouldn't show. Now all I get is this message, "File Upload: The file 'tattoo.jpg' could not be ingested because its media (MIME) type could not be detected."
Under item type I choose still image, I state the original format as photo, add the dimensions, list the format as .jpg, the type as Image, I've added the ImageQuick directory path, and I'm getting the image out of the images folder in my themes folder which is in my Omeka folder.. *deepbreath* Okay, so what could I be missing? Am I filling something out wrong? I would appreciate any input, thank you!

Nevermind, I found a similar thread and found that checking either the Disable File Upload Validation or the Enable Header Checks for File Types boxes in security settings solved the problem. So I am keeping the header box checked, this wont cause me any unrelated problems will it?