I have a big problem with data uploads. Whenever I try to use a Web site to do an HTTP upload, or use iChat or any e-mail client to send a file to another user, the following happens: 20-30 kb of the file is sent Upload stalls for 30 seconds Another 20-30 kb of the file is sent Upload stalls again A 1 MB file can take over 15 minutes to send, and sending larger files often causes timeout errors. The download speed is normal, but uploading is so slow that I have started putting files on CD and taking them to other people locally instead of trying to upload the data. This seems to be the same problem affecting my Folding work unit uploads. My modem hardware flow control is enabled. Someone mentioned that my MTU settings need to be changed. Could this be the problem, and where are those settings for an ethernet-connected Mac running OS X?