I don't think your TYPE check is correct. There is no 'M' for types. You better check for not being 'U' (undefined).

If you read the VFP help file, you will see that there is an 'M' type. This is from that topic:

Return value Data type
A Array (only returned when the optional 1 parameter is included)
C Character, Varchar, Varchar (Binary)
If the optional 1 parameter is included, a return value of C indicates that the data type is a collection.
D Date
G General
L Logical
M Memo
N Numeric, Float, Double, or Integer
O Object
Q Varbinary
S Screen
Note
The Screen type is created when using the SAVE SCREEN command. For more information, see SAVE SCREEN Command.
T DateTime
U Undefined type of expression or cannot evaluate expression.
If the optional 1 parameter is included, a return value of U indicates that the data type is not an array.
W Blob
Y Currency