There are a number of cautions when placing inserts in your loaf soap pan. 

Melting The Inserts:  Remember that most M&P soaps melt at between 115 and 130 degrees F.  This is the best temperature range to work with your soaps.  If you can't put your hand in the soap, it's too hot.  If you put your inserts in soap that is too hot, your inserts will melt.  When placed in soap that is too cool, the surrounding soap base will not stick to the inserts well and your sliced soap bar may fall apart during use or even during slicing.  Remember that you want the insert to begin to melt and then stop melting as the surrounding base cools.  The thicker the insert, the hotter you can pour the surrounding soap base.  You might think of this as welding the soap together.

The Soap Isn't Flexible Enough:  Many of the inserts are made by bending the soap at 90 degree angles or otherwise flexing them to the point where they craze or break.  This will happen when the soap is very cool or may just be a characteristic of the soap base you are using.  This tendency is even more common with opaque soap because the titanium dioxide used to whiten the soap may make it more inclined to break.  Normally your inserts will be made from colored soap base which you may pour onto a cookie sheet or cut from a block.  To soften the soap and make it more flexible, add 1 fl oz of tap water per pound when coloring the soap you will be forming into inserts.  This will make the soap more flexible.  When encapsulated into the loaf, the extra water will dissipate into the loaf evenly and will not be noticed.

My Curls & Other Inserts Have Small Bubbles On Them: Your soap contains both propylene glycol and glycerin.  Both of these ingredients attract moisture from the air which will form small beads of moisture on the soap.  The higher the dew point and the more moist the air, the quicker and more extensive this process will be.  Although this is bad for crafting, it is the process which the soap uses to moisturize the skin.  We would suggest that you use the curls and inserts immediately rather than trying to save them.  If this isn't possible, then wrap them in plastic or place them in an air tight container.  When inserting them in the loaf, we recommend that you spray them with soap lock or alcohol to help dissipate the moisture.  This will help them bind to the surrounding soap in the loaf.  For both loaf soap and molded bar soap makers, the Soap Lock will also kill air bubbles on the surface of theloaves and bars caused by agitation during pouring.  Just spray at the bubbles and they will disappear.