check your preferences to see if Use File Compression is turned on in the misc section.  Every now and then I load up a scene with dynamic cloth and it has become corrupted, meaning I need to run the sim again.

 

If this keeps getting in the way, and you just want to save the "final" position of the cloth (whatever frame that may be) I do the following :

Move to "final" frame of animation

Select cloth object

Choose file->export->wavefront obj

Tick "Existing groups in polygon groups"  this will ensure any cloth/hair/non material groups are not discarded

Clear your cloth simulation and hide the cloth object

choose file->import->wavefront obj

Untick scale to 100% of figure size, centre object and place object on floor

 

This will save a "snapshot" of your cloth and then import just that snapshot.  you could delete the old one if you wanted, and its simulation. But only do that if you are SURE you dont want any changes!

 

Was the first pose you used (that failed on the second object) have extreme joint bends?  for example hands on the head has the inside of the elbows intersecting each other, or sitting cross legged on the ground has the back of the knees intersection each other.  Under the arms in a "stand to attention" type pose intersects with the body.   Where ever these body intersections occur you have the possibility (likely) of the simulation going haywire due to the cloth being caught.
The simulator does have code to allow for this, and sometimes Poser's implementation works, however if the trapped polygons have more force excherted on them than fold/shear/strech and frictions allow the sim will go crazy.  you can tell when this happens because a frames calculation time with increase 10 fold. sometimes the slightest of adjustments fixes it (lowering fold or shear or stretch by .1)

 

There are methods to get around this, but they are not for the beginner ;)

TemplarGFX
3D Hobbyist since 1996
I use poser native units

167 Car Materials for Poser