I just noticed that Poser 8 is using 90% and up most of the time even when im not doing anything just letting it sit there idle. 

 Hm.. With only Poser, Trillian and GoogleChrome open (and minimized) they use somewhere between 8 and 14% of my processor. With Poser In a window and the rest still minimized it's around 57-61% - but RAM usage is very stable at 63% no matter if it's minimized or not.

This is with one single Alyson in the scene btw.

Poser.exe normally sits at 0% CPU for me.  In the released build, if you have the Separate Process render option enabled, it can happen that Poser.exe can crash but leave FFRender.exe still running, and it can consume 100% CPU for "a while"; this has been reported as a bug and hopefully will be fixed.

 I've had Firefly stay there after a crash L Most annoying since I wasnt' aware and tried to render again after restarting Poser. Only when nothing happened did I find out that it was still there, chewing up ressources like mad.

But 0%? I've never seen that, and it seems unlikely, too. Any program will use at least something to run... Right?

No, not unless it's actually calculating something that needs to be calculated.  If you're not touching the keyboard and nothing is "going on" in the application (e.g. dynamics simulation) then yes, it should sit there at 0% CPU usage until you have it do something.  This is true with pretty much all software except stuff like video games, which are normally always "doing something" (animating a high frame rate screen for example even if nothing's going on except grass being blown by the wind).

Its doing it again this morning with poser.exe running at high cpu usage.  The memory usage was at around 133k until i went to load in a scene of course then it went up.  I will check it again and just let it sit at idle for a long while and see if it ever drops.

Ok after I did a render then let it sit it drops to 0 LOL so it must be doing something or whatever but at least it is acting normal as of right now.

If you can figure out something that happens consistently you really should report it as a bug so it can get fixed.

If you have a light or a Camera selected in the Scene, Poser will use a core. The engineers are aware of this and you just need to make sure to select something other than a Camera or light before rendering in the mean time.