I recently installed the Smush.it plugin. Initially I was very pleased with it, but all of a sudden, uploading images (I use the browser upload) was either extremely slow (1 minute for a 30k JPG) or timing out (8 out of 10 times) with the error: Operation timed out with 0 out of -1 bytes received.
I found this article: http://wordpress.org/support/topic/plugin-wp-smushit-fix-for-timeouts-after-5000-milliseconds?replies=5
I disabled the plugin, and tested the upload function: Problem gone!
I understand from the article that this issue should have been fixed in a prior release, but apparently it's popping up again (new WordPress version?). I used Smush.it 1.3.4 with WP 3.0.4. Same problem and same fix on two separate sites. Does anyone know of a solution? Could it be a two-way problem between the plugin and the performance of my hosting party's server?