Since I didn't have to do anything special to make my report work... And, since the usually VERY helpful folk here haven't resolved this...
I suspect there are some special characters in your memo field causing the grief. To see if this is the problem, create a new table with the same characteristics. Then, copy a few records without the memo field to the new table. Next, copy/paste special a memo field at a time to notepad/wordpad/word - be sure to save as plain text. Then copy the plain text to the memo field in your new table. Run your report based on the new table and see if the result is different.
If I'm right, then you may need a VBA routine to cleanse your memo fields. There are many people contributing here who are more adept at helping putting that together.
Good Luck!
Bob (M.E.A.N.)
Moderately Exasperated Access Novice ;-)