Is it possible we can trigger an automatic size/mb reduction for images people try to upload that are too large?
Assuming that the problem is indeed caused by large file sizes, you can do that via client-side JavaScript code that automatically compresses the image file (or reduces its quality) before uploading, saving both the user and the D.Buzz server network bandwidth usage.
However, the questions remain. To what extent will you sacrifice the quality of each image just for it to be uploaded to D.Buzz? Why not just increase the file size limit of images uploaded using D.Buzz? Why did the problem actually start in the first place? The sleepy @chrisrice should answer it after he wakes up about 9 hours later.