reading data from specified ranges doesn't work

[tomato42]

when the -r option is used to specify ranges to test, like:

75000000 78165360

no statistics are shown:

reread 101.95% done in 00:01:01, expected time:00:01:00
reread 101.95% done in 00:01:01, expected time:00:01:00
reread 101.95% done in 00:01:01, expected time:00:01:00
         Samples:             Blocks (9th decile):
< 2.4ms:                    0                    0
< 5.8ms:                    0                    0
<14.1ms:                    0                    0
<22.5ms:                    0                    0
<39.1ms:                    0                    0
<55.8ms:                    0                    0
>55.8ms:                    0                    0
ERR    :                    0                    0
Intrrpt:                    3                    0


hdck results:
=============
no problematic blocks found!

wall time: 185s.95ms.393µs.764ns
sum time: 0s.0ms.0µs
tested 305333 blocks (0 errors, 0 samples)
mean block time: -nans.-nanms.-nanµs
std dev: 0.000000000(ms)
Number of invalid blocks because of detected interrupted reads: 0
Number of interrupted reads: 3
Individual block statistics:
<2.44ms: 0
<5.79ms: 0
<14.12ms: 0
<22.46ms: 0
<39.12ms: 0
<55.79ms: 0
>55.79ms: 0
ERR: 0

Worst blocks:
block no      st.dev  avg   1stQ    med     3rdQ   valid samples 9th decile
           0  0.0000   -nan     nan     nan     nan  no    0       nan
           1  0.0000   -nan     nan     nan     nan  no    0       nan
           2  0.0000   -nan     nan     nan     nan  no    0       nan
           3  0.0000   -nan     nan     nan     nan  no    0       nan
           4  0.0000   -nan     nan     nan     nan  no    0       nan
           5  0.0000   -nan     nan     nan     nan  no    0       nan
           6  0.0000   -nan     nan     nan     nan  no    0       nan
           7  0.0000   -nan     nan     nan     nan  no    0       nan
           8  0.0000   -nan     nan     nan     nan  no    0       nan
           9  0.0000   -nan     nan     nan     nan  no    0       nan

Disk status: excellent