[ganoushoreilly]

First, Document Document Document just to cover your ass internally (maybe email a recap of problems to yourself).

As for actually addressing the issue, Is there a shared Executive Assistant or Program manager on the teams you're reaching out to? One thing i've had success with is reaching out to one of their senior direct reports (when appropriate). I would usually say something like "Hi, There's an issue with XYZ, what are your thoughts on how we can improve it with the least impact to your team? I'd like to get this in front of Y as soon as possible, any thoughts?" What I found is that people are eager to get brownie points with the boss, leverage that and get your initiative pushed through the team rather than from outside the team. Again, I realize this doesn't work for every situation, but it's helpful.

Sometimes you just have to socially engineer the outcome you need.

Good luck!