I don't know what the GK bug is??? Never came across it.

Surely its not that complex (i'm no computer genius) but all it needs is an up/down arrow either side of a year when renewing them, say maybe have it set at 3 years but then the user can click up or down to offer more years or less.

Like someone said players happiness isn't effected when renewing a contract, so its not so much "negotiating" but just adding a few years on or taking a few off so managers can spread the cost of signing on fees over a few more seasons rather than just 2.