Melt butter in small saucepan and add garlic. (If you're not a huge fan of garlic, use chunks so you can extract flavor, then remove the chunks).
Add remaining ingredients (except salmon) and cook until sugar is dissolved.
If broiling: Place on broiling pan (raised rack with foil is good). Broil for about 5 minutes, then baste. Continue broiling for about 8 to 10 more minutes or until salmon is opaque and flakes with fork.
If grilling: Lightly oil grate. Place salmon on grill (medium heat) then baste with sauce. After 5 minutes, turn salmon and baste again. Continue turning and basting until salmon is opaque and flakes with a fork.
I thought I'd try this sauce to go with some smoked salmon steaks I'd bought on special. I was a little worried that it might be too sweet, but the slightly sweet/salty combination from the sugar/soy sauce worked extremely well with the smoked flavour of the salmon. I will definitely try it again with normal salmon fillets.