Vertex O series failure on v10

So our issues have been going on for almost a year. As it turns out we are one of two clients on S3 version 10, on a windows platform, attempting to use the Vertex O series. We have multiple environments and have not had any success with configuring, patching, etc getting the systems to talk to each other correctly. Our other integration's, which number in the 100's, run flawlessly.

The keep or toss moment is here as its' implementation is holding up several large initiatives and I was hoping you guys could chime in and perhaps point me in the direction of other sales and use tax vendors that have been used with Lawson S3.. We are fine using the TX module, but is there a vendor who provides on going updates that we can grab and load with an in house integration?

Thanks for your insight - appreciate your time!