What means "Length" in the properties page?

We have to measure the length of wavefiles in H:M:S:F.
This was no problem with 973 of 977 files. Only 4 files are greater than 4 GB, and are not shown in my filemanager (DOpus).
So I looked into Sonar what the propeties page says.
Now I notice that all values to the length of all clips are totally wrong (?) or I don't understand them ??.
I have set the time Format to H:M:S:F
A clip with 2 min 30 sec has the value of 20:54:06:19 (H:M:S:F).
A clip with 10 min 41 sec has the value of 00:10:25:02 (H:M:S:F) !!! instead 10:41 it says 10:25 !!!
A clip with 26 min 10 sec has the value of 21:10:49:27(H:M:S:F).
This would mean my clips are over 20 hours !!!
The values are independently from the position of the clip. The help-file says this values show the length of the clip in H:M:S:F format.
The clips are alle applied with trimming and bounced. So they are not longer as shown.
Have I misunderstood something - means "length" something else ?