With the server move we went from a 32-bit system to 64-bit. This means that some data types have changed size (esp. pointers); unfortunately, that has impacted multi-stage skills that involve a target (the target goes away, mid-way through operation). It doesn't crash us, but it does mean the skill will fail. There aren't a lot of skills impacted, but poisoner thieves are hit the hardest.

A single fix will most likely fix all the impacted skills, but it's also not a trivial "let's just do this" fix. It's being looked at, but we don't have an answer quite yet.