2.51.7:Can not display JPEG2000 in DICOM

[zaa29000]

XnView: Classic for Windows 2.51.7 - 32-bit
OS: Windows 7 - 32-bit

These 2 files
JPEG2000-RGB.dcm
JPEG2000-RGB.dcm.0001.bin.jp2
in attached zip .

XnView warn "JPEG 2000 compression not supported" when "JPEG2000-RGB.dcm" opening .
"JPEG2000-RGB.dcm.0001.bin.jp2" is simply extracted from "JPEG2000-RGB.dcm".
XnView can display "JPEG2000-RGB.dcm.0001.bin.jp2" exactly.

Effect: XnView display Warnings messages.

To reproduce:
1. Browse a folder for unziped "JPEG2000-RGB.dcm".
2. Drag drop to XnView icon.
Actual behaviour (bug): XnView warn "JPEG 2000 compression not supported"
3. Browse a folder for unziped "JPEG2000-RGB.dcm.0001.bin.jp2".
4. Drag drop to XnView icon.
Actual behaviour (No problems): XnView can display "JPEG2000-RGB.dcm.0001.bin.jp2" exactly.

Expected behaviour: XnView display JPEG2000 image in DICOMfile .