Cannot launch 1.8.1-pre1 with Java 8 (64bit). Java 7 works.

I can run MC 1.8 release perfectly fine with Java 1.8.0,
but on 1.8.1-pre 1 client can't get launched with Java 8.

See "Environment":
I tried out update 20 as well as the latest update 25.

Java 7 works fine on -pre1.

Launcher Log attached as textfile.
There is a German expression in there at the end of the log that I should translate:
"Zugriff verweigert" means: "Access denied".

Apparently -pre2 will get released by tomorrow.
I'll check launching -pre2 with Java 8 then again.

PS: I'm extremely terrible/too dumb in finding duplicates, but I really do use Mojira's search before I post anything. Super-sorry in case this bug was already posted.

Kind regards,
Meri