Thanks for bringing this to our attention.

This is a very strange one. It looks like a bug to me, and I submitted it for you. You can work around it by wrapping INT() around the AT() call.

lcField=FIELD(INT(AT("2",lcFldState,1))) 

What is really strange is subsequent calls also return the caption, even if you pass a number. This demonstrates:

clear 
close data all
erase testdb.dbc
erase testdb.dc?
erase testtab1.dbf
CREATE DATABASE testdb
create table testtab1 (f1 i, f2Name C(5)) 
=DBSetProp('testtab1.f2Name',"FIELD","Caption",'F2Caption')
?FIELD(2) && gives fieldname
?FIELD(AT("2",'12',1))  && gives caption, wrap with int() to workaround
?FIELD(2)  && gives caption unless you comment out or fix above line
?FIELD(Int(2)) && gives fieldname
return 

Passing a UDF rather than AT() works OK also.

>>>I just upgraded to VFP8 and I seem to have found another problem. There is a new parameter (nFlags) for the FIELD function that determines whether the field name or caption is returned. From what I see, it looks like the default is to return the caption, which is different than VFP7 and my code is crashing. This doesn't make sense - can anyone explain it?
>>
>>By default (w/o third parameter) the FIELD() function returns field name. Can you provide more details?
>
>My code looks like this:
>lcFldState=SUBSTR(GETFLDSTATE(-1),2)
>lcField=FIELD(AT("2",lcFldState,1)) (where AT("2",lcFldState,1) returns 42)
>
>I recompiled everything in VFP8. But when I step through the program, the value of lcField is the field's caption, not its name.