PHP Warning: addslashes() expects parameter 1 to be string

PHP Warning: addslashes() expects parameter 1 to be string, array given in .../public_html/store/includes/functions/functions_general.php on line 903

Hello, I'm getting the above warning in my logs folder, today I got 27 of the exact same error log during a 10 minute period that a customer must have been adding things to their cart, and in the last few minutes of this they created an account, with the errors before and after this event. They didn't end up checking out and I'm concerned that whatever this is will prevent them from checking out. Is this warning a huge deal, and is there any way to fix it?

I didn't change functions_general.php at all, it's the same as it came when I installed 1.5.3.

Thanks!

The function zen_db_input is the "victim" here; it's the caller of that function that's the "culprit". You can load the myDEBUG Backtrace (http://www.zen-cart.com/downloads.php?do=file&id=1879) plugin that will identify the culprit!

Ok, thanks so much! I installed it, I'll see what errors come up now!