Question : subform field linker error: "object variable or With block variable not set"

I have a problem similar to a previously posted question in 2003 ( id: 20799795), but I have not found a working solution.

In short, I have three tables tblA, tblB, and tblC.
tblA and tblB have a defined one to one relationship. tblB and tblC are related as one (tblB) to many (tblC) relationship.

I have created a frmA, fsubA, fsubB, fsubC.
frmA and fsubA use the same record source: tblA. (the purpose of this is to allow another level of Tab Control within a specific page on the top level Tab Control in frmA).
fsubA has a nested subform fsubB, which uses the record source of tblB.
fsubB in turn has a nested subform fsubC, which uses the record source tblC.

the PROBLEM arises when I try to define the subform linker field in fsubC, which I get the error message dialog "object variable or With block variable not set".

this problem only occurs when I do this from frmA. HOWEVER, even if I successfully define it from within the subforms (fsubA or fsubB). fsubC is not still not linked when I open frmA (the records are not linked/filtered and all records in tblC are shown).

what is wrong with this and how do I solve it?
I appreciate your help and expertise!

Answer : subform field linker error: "object variable or With block variable not set"

Actually the linker works if you manually type in the field names in the property window, it's just the linker wizard not working when it is beyond the 3rd level in subforms.