Amazon block % declining? Help

[~Lord``CoW~]

Well Iv decided to build myself a shiney new 1.10 overpowered Javazon, mostly for pvp, which requires a high rate of block as Amazon's defense... well... Blows.
I been leveling her like a madman making level 89 in 3-4 days and Iv been baffled by her block rate. I get her up to 72% thinking that last 3% worth of dexterity would be better spent in vitality, so I make what seems like a good decision in her final 11 levels of stat points. Yet alas, the block rate has been declining and all her gear has been the exact same since level 80. She went from 73% to 67% when I gained 9 levels!! This is rather discouraging.. Will it get so low that it is basically non effective? I know I am not the only one experience this strange problem as my friend deleted his amazon because of the same problem (anger managment anyone?)
If anyone could help me remedy this problem or tell me some way I could regain my lost/wasted block % I would be very greatful...

Out.
Cow

[Samka]

Block % is reduced proportional to your level. I don't know the exact rate, but to counteract it, you need to up your dex, or use items that increase your blocking chance.

[adeyke]

The block formula:

total block chance = (shield block * (dexterity - 15)) / (2 * clvl)

You just need a few points in dexterity each level to maintain your block chance.

[arrunique]

If you use additives like guardian angel and safety amulet you can crank up your shield block so you need less dex.