Miro

The PNG thumbnails Miro generates in the extracted icon cache are unoptimized (A Miro 38.KB PNG becomes a 9.38 KB JPG). Also this icon cache keeps all thumbnails, even very old ones.

There should be a "Clean Miro Thumbnail Cache" option that deletes all thumbnails that are no longer listed in the Miro library. :D

PNGs should be used, not JPEGs. If you want smaller filesizes, either increase the compression- reducing quality- or buy another 64MB RAM chip.

Or, you are welcome to join the 21st century, where 1992's JPEG is no longer needed. JPEG is a lossy format, PNG allows lossless compression :D

JPG is alive and kicking, and PNG is overused. Proper compression of a JPG produces not difference from a PNG to the naked eye when done correctly.  Then again, Miro is having a lot of problems doing "correct" the days.  

As to the 21st century, you mindnumbing binarry "either/or" thinking belongs in the 18th century. Go there and get out of the way until you have some real answers.