So, what do you do if you find something wrong with the SL viewer or sim code? This isn't WoW where you hit a button and leave a message for a GM.
You enter a bug report into the SL Jira. It's used for bug reports and feature requests, not technical support problems.
I personally find using bug tracking software this way to be offensive. It's not designed for customers. Many people have no idea what to pick from all drop down boxes or put in the text boxes, much less how to describe a software problem in a way useful for a software engineer. Customers often find the interface confusing. In my snarkier moments, I assume the goal was to cut down the number of bug reports by convincing people not to bother making them.
You have to be logged into the SL website to see jira listings, which means you're stuck using the built-in search engine. I'd rather use Google myself. (That's how I find things on the SLMarketplace. I love being able to shop on the web but hate the half-assed search function.)
For those of you who code, the LSL Portal links directly to jira bug reports relating to specific functions.
Once you're logged in, you can vote or comment on bug reports in the system. Voting is a way to express interest. You can also follow a report so you receive notification of updates or changes in status.