[carpeperdiem]

I use xp with elavon virtual merchant.
xp 1.0.6

xp payment config is quite simple:
Payment module: Virtual Merchant - Merchant Provided Form
set Initial transaction to auth & capture

merchantID is the same as elavon "accountID"
get the userid from elavon (I believe it is the same for all but for privacy I will not share it here)
get the PIN from elavon

that's it

myvirtualmerchant settings:

terminal > advanced > system setup

Use HTTP Referrers [ unchecked ]
Auto Pend HTTP Transactions [x]
Auto Settlement [x]

EVERYTHING else is empty

Try this.
J