Items Sometimes Disappearing From Cart After Logins

[missingDividends]

I put together a pretty standard OsCommerce setup for a business owner, and lately they've started receiving complaints that items disappear from their shopping cart after they create an account or login.

 

After quite a bit of testing and research, I haven't found a specific cause for this (sometimes items disappear, sometimes they don't). I couldn't find anything about this after some quick searches, but is this a known issue, or can anyone think of a work-around?

 

Any help or suggestions would be appreciated. If there's any information I could supply that might help, let me know. I'm hoping that I'm not the first person to run into this issue, but I guess it's a possibility.

 

Regards,

MD