From this website...
http://www.24carat.co...shouldersofgants.html
"We have been asked quite a few times now about two pound coins with an edge error. The letter I in GIANTS appears to be missing, so that the edge inscription reads:-
STANDING ON THE SHOULDERS OF GANTS
instead of:-
STANDING ON THE SHOULDERS OF GiANTS
Most people finding these expect that they will be worth fortunes. This error appears to be relatively common, and there are not many coin collectors who specialise in collecting errors, so this error will not be valuable. We did speak to another dealer recently who told us that he had found some in mint coin sets which he had sold for £8 each. In circulated condition they are worth keeping only as a curiosity, and will have little value apart from their £2 face value.
The cause of this type of error is quite simple, and fairly common. The edge inscriptions are impressed into the edge of the coin blanks before the blanks are struck. The edge lettering machine rolls the coin between steel rollers bearing the inscription. As with any mechanical process, wear and breakage is possible. Because the letter "I" is thin, there is little lateral support, and therefore it is more likely that the raised letter "I" on the roller will get broken off than any of the other letters. Coins are mass produced and not subject to individual inspection. It is therefore quite easy for a large number to be made before the error was noticed, and it is unlikely that the Royal Mint would have considered it worthwhile to scrap and re-mint any faulty coins, of which there may have been tens, or hundreds and thousands."