(title is supposed to say "whenever I upload a file")

I'm running Slackware 10.0, I'm using a Modem Blaster DE5621 serial modem, my connection speed is 28.8 kb/s. Every time I try to upload a file more than a few hundred kilobytes my internet connection locks up. Nothing uploading, nothing downloading, even after I close the program I'm uploading with. With an FTP program, it locked up at 71% of a 183 kb file. I can make the same uploads sucessfully in Windows, so the problem must be specific to something in Linux. Any advice? I'm at a loss for ideas here.

as soon as ur connection stops working
run this

tail /var/log/messages

this will give u the last log

and see if u can find anything that is is a problem

regards