[ferret_users] Whether this is bug in Ferret ? or I am doing something wrong ?

I am interested to merge file, this is what I have done, let me know if I am doing wrong here...

[akshay@aix ~]$ f
    NOAA/PMEL TMAP
    FERRET v6.85
    Linux 2.6.18-371.1.2.el5 64-bit - 11/12/13
    6-Dec-13 16:49

yes? use test_1.nc

yes? sh d
     currently SET data sets:
    1> ./test_1.nc (default)
name     title                             I         J         K         L         M         N
TEMP     Temperature                      1:5       ...       1:2026    ...       ...       ...

yes? sh g temp
    GRID GBN1
name       axis              # pts   start                end
PROFILE   X                    5 r   1                    5
normal    Y
DEPTH_LEVEL DEPTH (m)       2026 r- 0                    2025
normal    T
normal    E
normal    F

yes? let c1=`temp,return=istart` ! start is same as that of sh g temp start
!-> DEFINE VARIABLE c1=1

yes? let c2=`temp,return=iend` ! end is same as that of sh g temp end
!-> DEFINE VARIABLE c2=5

yes? list/file=test_2.nc/format=cdf/clobber/keep_axisname temp[i=5]
LISTing to file test_2.nc

yes? use test_2.nc
yes? sh d 2
     currently SET data sets:
    2> ./test_2.nc (default)
name     title                             I         J         K         L         M         N
TEMP     Temperature                      1:1       ...       1:2026    ...       ...       ...

yes? sh g temp[d=2]
    GRID GAY1
name       axis              # pts   start                end
PROFILE1 X                    1 r   5                    5
normal    Y
DEPTH_LEVEL DEPTH (m)       2026 r- 0                    2025
normal    T
normal    E
normal    F

yes? let c1=`temp[d=2],return=istart` ! whereas this is not
!-> DEFINE VARIABLE c1=1

yes? let c2=`temp[d=2],return=iend` ! whereas this is not
!-> DEFINE VARIABLE c2=1
yes?

and then merging

yes? use test_1.nc
yes? sh d
     currently SET data sets:
    1> ./test_1.nc (default)
name     title                             I         J         K         L         M         N
TEMP     Temperature                      1:5       ...       1:2026    ...       ...       ...

yes? list/file=merge1.nc/format=cdf/clobber/keep_axisname temp[i=3]
LISTing to file merge1.nc

yes? list/file=merge2.nc/format=cdf/clobber/keep_axisname temp[i=5]
LISTing to file merge2.nc

yes? canc data/all

yes? use merge1.nc ; use merge2.nc

yes? sh d
     currently SET data sets:
    1> ./merge1.nc
name     title                             I         J         K         L         M         N
TEMP     Temperature                      1:1       ...       1:2026    ...       ...       ...

    2> ./merge2.nc (default)
name     title                             I         J         K         L         M         N
TEMP     Temperature                      1:1       ...       1:2026    ...       ...       ...

yes? sh g temp[d=1]; sh g temp[d=2]
    GRID GBM1
name       axis              # pts   start                end
PROFILE   X                    1 r   3                    3
normal    Y
DEPTH_LEVEL DEPTH (m)       2026 r- 0                    2025
normal    T
normal    E
normal    F
    GRID GAV1
name       axis              # pts   start                end
PROFILE1 X                    1 r   5                    5
normal    Y
DEPTH_LEVEL DEPTH (m)       2026 r- 0                    2025
normal    T
normal    E
normal    F

yes? list/file=merged_file.nc/format=cdf/clobber temp[d=1]
LISTing to file merged_file.nc

yes? list/file=merged_file.nc/format=cdf/append temp[d=2]
LISTing to file merged_file.nc
**TMAP ERR: error in line definition
             file coords dont match variable coords on axis PROFILE
yes? q

If I open file one after another individually

[akshay@aix ]$ f
     NOAA/PMEL TMAP
     FERRET v6.85
     Linux 2.6.18-371.1.2.el5 64-bit - 11/12/13
     6-Dec-13 16:55

yes? use merge1.nc
yes? sh d
     currently SET data sets:
    1> ./merge1.nc (default)
name     title                             I         J         K         L         M         N
TEMP     Temperature                      1:1       ...       1:2026    ...       ...       ...

yes? sh g temp
    GRID GBM1
name       axis              # pts   start                end
PROFILE   X                    1 r   3                    3
normal    Y
DEPTH_LEVEL DEPTH (m)       2026 r- 0                    2025
normal    T
normal    E
normal    F
yes? q
[akshay@aix ]$ f
     NOAA/PMEL TMAP
     FERRET v6.85
     Linux 2.6.18-371.1.2.el5 64-bit - 11/12/13
     6-Dec-13 16:55

yes? use merge2.nc
yes? sh d
     currently SET data sets:
    1> ./merge2.nc (default)
name     title                             I         J         K         L         M         N
TEMP     Temperature                      1:1       ...       1:2026    ...       ...       ...

yes? sh g temp
    GRID GAV1
name       axis              # pts   start                end
PROFILE   X                    1 r   5                    5
normal    Y
DEPTH_LEVEL DEPTH (m)       2026 r- 0                    2025
normal    T
normal    E
normal    F
yes?

Any solution/comment/compliments will be appreciated .

Akshay