Merge from Clipboard ?

[toyL]

need some help here, please...
...…I'm well into the sx learning-curve by now and beginning to lose hope that ignorance is my biggest problem…I have a few questions so far, but I'll just post em' one at a time...
1) it seems that each time I've used "Merge from Clipboard" the resulting paste has lost some of it’s level--roughly 3dB...by itself this might not be a big deal; however, I soon discovered that simply raising the level back up by clicking on the handy-dandy(?) Gain feature unerringly introduces distortion...any suggestions?…thanks.