[axis2-1.6.1] java MTOM client very slow compared to .NET WCF client

Hi all,

I've developed a MTOM Client server apps sending up- and downloading
larger files.

Doing some performance testing 
I toke 25 MB files and did some up and downloads routinely using
dispatch and proxy approaches.

The outcome was very nice, 
I had a java client working uploading axis2.zip (25MB) 
to a OpenVMS Java web service server within 5 to 8 seconds.

Generating a stub in Visual Studio delivered me the same. A very
performing CL/SV transfer aps, 
and the Vista task Manager showed close to 100% network utilization.

Since a few days however, this is no longer the case for the java
client, 
the network utilization has degraded to 1 to 2% and now the same
transfer takes 
4 to 5 minutes. Unacceptable.

At the same time absolute no problem and close to 100% network
utilization if I run my Visual Studio Test Suite of proxy based up and
down load tests.

If I changed something on my client side java code, that would be
unintentionally. ! :-)

But any hint where I can start to hunt this phenomena would be very
appreciated?

I am launching my java client within NetBeans 7.2.1 for debugging and
testing reasons, 
also it the past it was working so nicely.

There is maybe one point I can make: 

When I used the NB debugger, I could see the
 "MultiThreadedHttpConnectionManager" doing some cleanup 'running'
forever.

What makes him running?

Fiddling a bit around within the debug-view, 
I have seen an immediate Network utilization going up to 100% 
when this manager was suspended for a moment.

as I have no clue what has happen then or how to catch it any hints are
very welcome.

Any hints welcome.

Regards
Josef