Version:           0.12.15 (using KDE KDE 3.5.3)
Installed from:    Debian testing/unstable Packages
OS:                Linux

This bug was reported by Andreas Beckmann <debian@abeckmann.de> on the Debian bug tracker (http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=367788).  It looks similar to bug 123799 (http://bugs.kde.org/123799) but the FIFO buffer also shows "no info", which seems to cause some problems with the burned CDs.  I could not reproduce the problem on my machine but perhaps here it is, in case you would like more information to track this down:

My burner is a MATSHITA DVD-RAM UJ-841S.
When I burn data DVDs I have never seen a Device Buffer indicator (only
'no info') and the FIFO Buffer indicator showed the bar during a few
burns and 'no info' during others. Burning different projects with the
same settings and with or without restarting k3b may result in a few
burns with the FIFO indicator showing something and a few showing only
'no info'. So far I can't remember seeing the indicator showing data after
a burn with 'no info'.
Another interesting observation is the following: an older drive
(PIONEER DVD-ROM DVD-115) in another computer successfully reads all the
disks that were burned with a working FIFO Buffer indicator, but none of
those that were burned while it showed 'no info'. The burner itself
reads all disks just fine.

I'd like to find the differences between the two burning modes in order
to use only the preferred one (with working FIFO Buffer indicator and
readability in the Pioneer drive) in the future.
The missing Drive Buffer indicator is not a big concern.

If there is any additional information you need or something I should
try to help debugging this problem, please let me know.