Perplexing runtime 3011 error

[mitchem1]

I have a simple database that opens with a main window displaying 5 buttons that can open 5 different forms. I have created 2 security groups -- one that allows full access and the other read only. When logged in as a Read Only user, there is one form that spits out a runtime 3011 error, could not find the object. The security for this form is the same for all of the other forms, tables, queries, etc. which all open fine. The form opens fine when logged in as a full user, so obviously the object is there. I can't figure it out and am losing my mind. Help!