I bought a Freud S208 on eBay for $74.

I used it last week to cut some 3/4" dados in butternut. It was perfect.

Today I did some 5/16" in red oak. The bottom was uneven (I used the 1/16"
cutter, last week I didn't; maybe it cuts high?) and there was serious
tearout on the ends.

This was my first time with a dado set; I have always used a router before.
Is it typical, or is the S208 just not ready for prime time? (or am I doing
something wrong?)

Thanks.