Have had requests from users to get today's SA backported from D6. I'm creating this release to allow people to submit issues against 5.x but have no intention of providing active support for D5 beyond the SA. I will accept patches.
This code should be considered untested and likely has variations from the code in uc_migs3rdparty which this module was based on.
There have been multiple reports of the old contrib module being rejected by MIGS staff because it does not correctly validate the transaction details (ie, you can fake the transaction amount and not upset the validation code). This is issue #568338 and should have been resolved in this release.