Percentage of File System Space Used on HP System Management Homepage reports incorrectly

[Andreas Meyer]

Hello,
I have a Proliant DL380 G5.
On the HP System Management Homepage of the Server I go to
File System Space Used.
There the three volumes are listed: c: d: and e:
Volume e: is a (Hardware) Raid-5 (underneath)
The line for e:\ reads like this:
Used Space: 311219 MB
Unused Space: 204881 MB
Total Space: 516100 MB
Percent Space Used: 27%
The calculated 27% in the progress bar obviously are very wrong.
HOW CAN I CORRECT THIS??
Of course, Insight Manager on my client machine also reports the incorrect percentage.

Thank you for any ideas that help correct the percentage.

Andreas