There is a quirk in the enchant/reinforce rates that i pointed out toin the forums using the raw data from the Rohan client. The base rates are decent up to +5, but never 100%. they drop to about 20%, then jump back up to 80-70% all the way to +9 then drop off at +10 to about 15%, then jump back up to almost 70% until after +12.

There are parameters they can supply on a per-server basis at the server side to move those closer to 100% for the lower levels, but that dip at +6 really kills a lot of people.