Image Not Copied When Copying Records

This behaviour us by design - you cannot pre-populate file upload field in the browser. You can only populate text boxes, dropdown boxes, check boxes etc. This means images/files won't be copied when you copy a record.

Is there definitely no way around this?
Within the CopyOnLoad function, is there anyway I can retrieve the ID of the record I have copied from? My plan is to store this value in a session variable and then use a custom SQL statement in the "After Record Added" event to generate the location of the image from the original record.

Sure, you can definitely do something like this. Check CopyOnLoad event documentation to see how you can find what record is being copied:

http://xlinesoft.com/asprunnerpro/docs/onload.htm
There are a few questions you need to answer:

• do you want two records to point to the same image or you need to create a copy of physical file as well?
  
• what to do if user decides to upload a new image. You need to make sure you do not override it.

I have read the documentation but it is very vague. How exactly do I access the ID of the record I am copying from?
"where - WHERE clause that points to the record to be copied. Example: ID=19." - Can you elaborate on this a little?

Sorry, I don't understand what exactly is not clear.
The typical SQL Query that retrieves one record looks like this:

where parameter contains the value of WHERE clause without the actual word WHERE. You can use it to build your own SQL query and retrieve values from the database.