Blu-Ray from FCP X

I tried to write to a 25 GB Blu-Ray BD-RE to be shure if it fails I don't lose a disk. I used a Verbatim disk. Now just today I read in the German Macwelt that Verbatim uses LTH who gives the most problems. I failed to write. I also tried Toast 11 with this disk. Failed also.
Now a few weeks ago I updated FCP X without thinking and later I read that it was better to wait for some reason. Is it now a FCP X or Verbatim problem.
I also tried to order a Panasonic disk from Amazon UK, but they charge 16 pound to ship 1 disk.
The problem with FCP X gives an error after 2/3 writing.
The text is:

The drive reported an error:
Sense Key - HARDWARE ERROR
Sense Code = 0x44
INTERNAL TARGET FAILURE

The drive is an external Pioneer for which I used Firewire and eSata cables. Nothing worked. I still don't have a Blu-Ray disk.

Who can help?

It could be a burner issue. Not all Blu-ray recorders can handle BD-RE apparently.
What burner are you using?
Have you tried a different burner?

The burner is a Pioneer BDR-205 and I don't have a second burner.
I'll buy new ones not from Verbatim.

I've quit using LTH discs as it appears to be a "compromised" technology intended to save the manufacturers a bit of money, possibly at the cost of compatibility:

[en.wikipedia.org]

FCP 7.0.3, PPro CS5.5, MPro Octo 2.8, 16 gigs RAM, Matrox MXO2, Sony EX1