Oscar_Zeta_Acosta:
I'm using this solder http://m.ebay.co.uk/itm?itemId=161281534343I have been using 350C temp on my hakko fx888d iron. I see the solder melting point is 183C. Is this perhaps one of the problems?
Specifications
63/37 rosin core solder.
Flux 2.0%.
Wire diameter: 0.8mm.
Melting point: 361°F/183°C.
Everything sounds fine, iron, temperature and solder specs. Whether the solder specs from eBay can be believed is anyone's guess. Personally, I wouldn't use no-name solder from eBay on a bet.
I'd get some real solder. This is my favorite. New parts that aren't visibly oxidized should not require cleaning. This solder has a more active flux if needed.
For through-hole work on new parts, additional flux is not usually needed, but it's a good idea to have one of these around just in case, and I do use it a lot for SMT work. This flux is a bit more active for those tougher jobs. While you're at it, get some desoldering braid.
Don't give up. Get some solder of known quality and try it again.