I think I found a very serious bug with automatically adding the coupons to cart feature.
Since there is no way to remove automatic coupons from the cart, if for example you set a Usage limit per user to 1 a customer who has already used this coupon will not be able to make a future transaction until the coupon is no longer added automatically. This feature does not let you remove the coupon and it does not let you check out either, it just displays the message ‘Coupon limit has been reached’ and then immediately after adds that same coupon again (displaying the message). The customer is then stuck in an endless loop unable to make a purchase. Please advise.
>If you want a ‘first order’-only coupon, this option has been added in the development version of 2.6.
A first order coupon is already supported in earlier versions by using an autocoupon with Usage limit per user=1 (and say minimum spend=1 which ensures that the coupon is removed when you remove the last paid item from the cart)..
.. at least I use that and it seems to work