Seems to me I ran into this once before, but can't remember how I fixed it.
Like any good programmer I had a report in a database that was almost exactly what I needed for a new database. I copied the report into the new db, and then changed all the needed controls, record sourcing, etc. When completed the report had all the old controls changed to the new db. After saving, when I tried to open the report I get a series of "Enter Parameter Value" boxes asking for parameters from the old database. I've carefully checked that none of the old parameters appear anywhere in the new db, and that there are no residual filters that might reference them.
The old db was in 2002-3 format as is the new one so it can be used by older systems. I'm working in Access 2010. Where am I not looking, to get rid of those old references.
Thanks, you reminded me that I'd been forced to create a whole new report that last time.
However, The SOLUTION was to recheck the Grouping specification, and found that although the new table showed none of the old fields, it had a blank spec and internally must still have had the old fields even though they didn't show. Recreating the sorting/grouping with the new fieldnames did the trick.