I opened my new site on Saturday, got some customers who purchased items - that has a nice sound to it! - and most seemed to go very smoothly.

One customer, however, has not been able to download the products without getting timed out and told to log back in.

He is using dial-up, the files are about 5 MB in size, and he gets about 800 KB before getting kicked off after 20-30 minutes

Here is what he sent me regarding his problem:

It is where your site times out after 20 to 30 minutes and requires you to login again. I hope I am explaining this right. When your site times out and requires you to login again it stops the download. Tried it 3 times and got around 800kb when the timeout and login happens.
I looked at the session settings in Admin/Configuration/Session and they looked OK to me - except that the Session Directory was set to a file on my local server! - even though this is the online server site...I changed it to "/tmp", and have sent a request that he try it again - but is this the likely cause? I see several threads on this kind of thing but happening on checkout using PayPal - and these downloads are free with a coupon he is using.

I also suggested he move around the site every few minutes, to avoid any inactivity timeout.

He's in Europe so I'm not sure how long it will take to hear from him - but for my own information, should this solution actually take care of the problem?