Struggling with wipeouts

[crbateman]

I have started using wipeouts in my symbols library, and am running into problems... When I introduce a block containing a wipeout into a drawing, the wipeout area does not match the shape of the wipeout pline, but instead takes the shape of a square (or rectangle) of a size and dimension of the entire block. That is to say, a circular symbol with a pseudo-circular wipeout (comprised of a closed polyline with 100 linear segments) shows in the target drawing surrounded by a square, rather than circular, wipeout.

Can anybody suggest what I might be doing wrong?

Thanks in advance!

EDIT: I should add that, besides seeing this on blocks inserted with contained wipeouts, the same thing occurs if I create a new wipeout in the drawing. The masked area is displayed as a rectangular area, with the overall width and height of the wipeout pline.

I have also discovered that this problem does NOT occur with every drawing. All the files I work in have been passed to me by other firms, and most work fine, but certain files do not. Could this be a variable or other setting native to an individual drawing causing this?

EDIT #2: OK, have discovered some additional weirdness... In those drawings where I am having trouble, blocks with wipeouts are being brought in when the "Frames" setting in wipeouts is set to "Display, but do not plot". If I change the setting to "Off", wipeouts display properly, following the contours of the wipeout polyline. Then. if I go back to "Display, but do not plot", wipeouts are now displayed as they should be. Something about changing the Frames setting, and then changing it back, makes everything right with the world. The mystery continues...