Everyone gets accused of cheating eventually, you just have to ignore it... if it bothers you abnormally make a point of reporting it to a moderator.
I've been accused of cheating on several occasions myself, in fact, one site even banned me for it! Looking back it's all kinda funny. Just have fun and don't let the occasional sore loser bug you.
I am relatively new to online chess (approaching a year on several free servers including yahoo, fics, ficgs, playchess.com). I've heard a lot of talk about cheating which I assume is just using a chess engine to pick your moves for you. Twice I've been accused of cheating on games where my post-analysis (I do use an engine for this) showed major blunders for both sides (including apparently cheater me).
First of all, what possible motivation is there for cheating?
Second of all, what types of clues make you suspicious someone is getting help?
Is cheating more common in blitz (on FICS I am 500 points higher on standard than blitz even though I never play faster than 8 0 and on standard never player slower than 20 0)