I've done the same thing. If you aren't REALLY careful on installation, you can pinch the tube between the tire bead & the rim. The advice from [MENTION=77386]prathman[/MENTION] to inflate to only 5 psig & then check the seat is excellent. I normally then deflate & look closely again. If everything looks good, I inflate to 20 psig to check the valve position in the rim. If the valve is at an angle, I deflate again & rotate the tire/tube on the rim until the valve is straight. Third try goes to full pressure.

Since I began the "three-stage" inflation method, I've not pinched a single tube in many, many tire/tube swaps. Experienced guys can probably do as well with a single check @ 5 psig, but I'm a klutz!