is it common for rear brake calipers to seize

You have rear calipers? well this being the case would have a "brake guy" disassemble the calipers and coat the slides with the lithium grease with a small brush and put them back...if they were siezed you'd want to replace them anyways~

Judge Roy is right, and the other answer is no, it's not common

four wheel disc...still cannot believe it....drums are much cheaper to manufacture and only do about 38% of the braking, that's why importance is never placed upon them~ probably they thought "Let's get with the times" tho, the Toyota Prius has Rear Drums~~ain't that a hoot~