Earlier this year there was a thread about someone who got a replacement trunnion from Ridgid that seems to clear up the problem:
http://lumberjocks.com/topics/58529
Unfortunately though, it seems that the OP was turned off by some rude LJ'ers, so they don't seem to still be around to answer additional questions.
The gist of it seemed to be that he got a replacement trunnion that had a "II" stamped on it.
Two things to keep in mind though
- the original post was from Feb of this year. IF (and that's a BIG IF) Ridgid made a change to the production line, it might not have shown up right at that time. It's likely they would have run through an existing supply first, if they even had plans to include the updated part in new saws
- several posters in the thread mention that they called Ridgid and were told that no such fix exists
It's very possible that the front line techs that Ridgid has answering the phones doesn't know anything about this, but I'm also just as inclined to believe it's not something they rolled into the production line.
If you're willing to put forth the effort, I'd find a Home Depot that's willing to let you check one out in the store and don't purchase it unless you see the updated trunnion. It's too risky to buy an older one with the hopes that you might be able to get a replacement trunnion. Additionally, it doesn't make a whole lot of sense to buy something you know will immediately need to be fixed. The box of these saws have a manufacturing date code on the label, and if memory serves me correctly, it's in the format of "EM20XXYY", where XX is the 2 digit year, and YY is the week of the year. I'd try to find one with a date as close to today as possible. Seeing as to how these are shipped on the slow boat from China, chances are the best you're gonna find is EM201436 or thereabouts.
It's an unfortunate situation if you ask me. I tried out a 4512 about 2 years ago that did have the alignment / blade shifting issue. That issue aside, it did seem like quite a decent saw for the money. Another issue frequently brought up is the split rail, however that can be corrected with a Delta T2 fence when budget permits. The alignment issue? Not so much.
The Delta 36-725 wasn't available at the time, but if it had been, I probably would have taken a look at that one after the Ridgid didn't work out for me.