Originally Posted by: JohnGCI am so surprised that I had three packs with the same problem.[/quote]

In my experience that can sometimes happen before you even buy them. Most strings are manufactured & packaged in large batches. If a whole batch of them sat in a warehouse for months after being made before they got to a store shelf or were sent to you, then the corrosion could have happened before you even got them!

That's why I suggested the possibility of exchanging them. I've had some success with that in the past.

Originally Posted by: JohnGCMaybe I should not keep them on standby and buy them as and when I need to change them. Keeping them at home for at least 7 months in a humid situation ( Queensland Australia ) could be the problem even though they are in a sealed pack.

Yes, keeping them on hand that long in a humid environment could also be the main factor! Buying & using them as needed might be best in your situation.

[quote=JohnGC]I will take your advise and try to remove the rust and use them.

Good deal!