Problems With ABS() Function Inside Sub Query (within WHERE-Clause)

Hello,

when trying to execute the following query with SQL CE 3.1 and OLEDB on WM2003:

SELECT C.Panel_Id, C.Panel_Tier, C.Panel_Type, C.Panel_No, C.Panel_Position
FROM tblMeasurements AS A, tblAssignment_Ant_Pan AS B, tblPanels AS C
WHERE (A.Measurement_No=?) AND (A.Antenna_No = B.Antenna_No) AND (B.Panel_Id = C.Panel_Id) AND C.Panel_Position in
(SELECT Panel_Position FROM tblMeasurement_Results
WHERE (Measurement_No=?) AND ABS(Measurement_Value) BETWEEN ? AND ?
GROUP BY Panel_Position)

i get this error returned:
0x80040E1DL -- DB_E_UNSUPPORTEDCONVERSION -- Requested conversion is not supported.

I don't know where inside the sql string a conversion is necessary/fails.
Surprisingsly when i modify the sql statement a little, it is executed WITHOUT ERRORS:

SELECT C.Panel_Id, C.Panel_Tier, C.Panel_Type, C.Panel_No, C.Panel_Position
FROM tblMeasurements AS A, tblAssignment_Ant_Pan AS B, tblPanels AS C
WHERE (A.Measurement_No=?) AND (A.Antenna_No = B.Antenna_No) AND (B.Panel_Id = C.Panel_Id) AND C.Panel_Position in
(SELECT Panel_Position FROM tblMeasurement_Results
WHERE (Measurement_No=?) AND Measurement_Value BETWEEN ? AND ?
GROUP BY Panel_Position)

The only difference between the 2 statements is the ABS() function inside the sub query.

More surprisingly, with the query analyser on the PDA i can execute both statements fine. I am absolutely confused now where i have to search for the mistake.

I would appreciate it very much if someone out there knows an answer or a hint and could tell me.

With kind regards,
Andre