As it says.

As we know 'keeper's sometimes go up for corners in the last munute to try and grab a goal. But can anyone remember ever seeing or hearing of a 'keeper being caught offside?

Never seen one offside, but the closest I can come up with was Dragoje Lekovic, playing for
K!lm*rn%ck against Ayr in a league cup tie in August 1996 when he tried to do a Maradonna and punch the ball into the net. Needless to say the big cheat was penalised. Think he was booked, but should have been sent off. Louis Thow would have sent him off

Can't be offside from a corner

The ball would almost always go backwards anyway.

Not straight from the corner kick but if the ball is cleared but quickly played back into the box the goalie could be caught in an offside position. Never seen it happen though

Don't know about offside but Goram and MacGregor (to name but two) have been caught doing pretty much everything else.

On February 4, 1997, in an FA Cup fourth-round replay, Manchester United were trailing going into injury-time when Schmeichel did his usual cavalry charge. After a deep corner was headed back into the box by Gary Pallister, Schmeichel sent a spectacular scissors-kick flying into the corner - only to be flagged offside, with about four other United players.