I honestly was happy to read this.
I use 6.3.1 with X3c 32-bit in Windsor 7 64-bit and receive no issues as of now (fingers crossed hard).
I would like to use X3c 64bit, but I do NOT want to update my software because things work right now and I continue to see UAD issue threads on here.
I think Cakewalk should employ CakeAlexS haha. Dude, or dudette, has been all over the baords trying to hunt and solve issues like a bandit. Awesome! However, without owning any UAD hardware and using it very regularly, as I and many other do, please keep in mind we are all mostly thousands of dollars invested into this system of plugins and are kinda peeved about issues that hang around for months.
If you think about it, we have all invested more into UAD than Cakewalk because their hardware and (mostly) all of their most-used plugins are pricey relative to the competition. So when things continue to be buggy, this board is our only outlet.
Finally, I will say that UA is awesome for support. If you have an issue, call em. Only reason I haven't called to ask is because I live in Canada and it costs to much to ask about 'potential' issues haha