fatal error. trial

My problem, after installing the demo and played with it. Loving it. I download the 30days free trial. This is when the strange stuff happens.
First I get this
“Plugin could not be activated because it triggered a fatal error.”
But somehow the plugin got activated, works fine and Im able to check it out, and im very happy to see the extra functions.

But then the weird stuff starts. I’m getting “whitescreen of death”, everything just goes blank when I’m browsing around in adminconsole. This is all at random. Could be 3 clicks or 30. It’s working again when I refresh the browser.

And another thing, The user file / uploader is not working, it’s not finding the files that are uploaded.
Works fine when I use the demo version.

I have tried to uninstall and redo everything, in correct order but to no help. And also tried a fresh install of wordpress (on a different one.com page I got. But when I try to activate the trial its giving me the fatal error and the weird stuff starts again.

I’m using : 1.6.0 demo + 3.0.1.6.trial.

best regards Marcus

http://ww.wp.xz.cn/extend/plugins/sp-client-document-manager/