There are too many to be listed on the margins of MO.
Look at the archives of the newsgroups comp.soft-sys.math.maple, comp.soft-sys.matlab, sci.math.symbolic, comp.soft-sys.math.mathematica. There you can find hundreds of bugs reported.
There is a notorious CAS bug hunter who once maintained a bug list for Maple and shows more than 5000 disturbing observations. (Press the Go! button.) Or go to MapleSoft and search Maple Primes.
Please don't shoot the messenger.