SQL Benchmark (oracle) twice as slow!

[mzi]

Hi

I use otrs 3.0.5 with CentOS 5.5 (OpenVZ VM) and Oracle 10.x (mod_perl enabled).
I followed the FAQ http://62.146.52.70/otrs/public.pl?Acti ... &ItemID=59
When I run the SQL Benchmark every time I get results twice as slow as it should, the rest of the web portal seems to be quick.
There are a few test tickets but not much!
I'm worried if the workload increases the response isn't that quick anymore.
If I enable http://faq.otrs.org/otrs/public.pl?Acti ... ItemID=331
"pre establish database connections" otrs isn't working anymore.

What could be the problem that is causing such high times in the SQL benchmark?

Thanks in advice.