This past week, I ran into a situation that I have seen in the past, but never quite grokked fully.
At The Job, the tech support organization is fairly savvy in the ways of computers, so they have a good number of programs and scripts they use to gather data on issues, fix known problems, etc. What happened was that there was a customer experiencing a problem, and Tech Support had written a script that fixed that problem, running nightly. The customer was happy.
What caused the problem was that Tech Support did not come back to development and let us know that there was a problem ongoing that they were covering for. So the problem festered, and now we have a deadline and a problem that we do not have time to fix and run through our QA process in time.
So when you are talking to your Tech Support people, be sure to ask them if there are any ongoing issues that they are handling that might be fixable in the product code, so tha you can solve them before they become big issues. The Tech Support people usually love to be the fixers, but they sometimes let that override their duty to report things up the line to get real fixes.