I've been having a problem on our site off and on and I think I've pinpointed it to something with cookies, but I wanted to get a second opinion.
I've got a custom cart designed on our site and every now and then, an order will come through just fine, but some information will be missing. Or, other times, the entry will get put into the database, but every field will be null. Same thing occurs for member signups as well. To attempt to find out why this was occuring, I'm now checking browser versions and logging anything put into database with that information. So far, there has been no relation as different browsers have the same problem.
The odd thing is that I can't recreate this at all. I've tried time and time again to recreate the problem and I can't make it happen. Everytime I do anything as far as signup or buy, it works perfectly.
My theory is that since sessions still require cookies to be enabled, some people don't have them enabled, and its causing problems. Either that, or there are momentary hiccups when the code tries to enter things into the database.