I recently released an update to some software and a bug slipped through the net. It introduced some odd behaviour with a control named SmartGrid. After some testing I was able to determine that it wasn't my fault and that I could reproduce a bug in SmartGrid. I hate bugs in other people's source code, I can't fix it, I am at their complete mercy.
Thankfully the Resco support was amazing! I posted on their forums and immediately someone sent me instructions on where to send my project. The next morning I was disappointed to see an email saying that the project worked fine. I posted again and almost immediately someone had offered to chat on skype.
We did that for a while, both confused by the problem. We then went on to use Remote Assistance so that he could observe my bug which he wasn't experiencing.
In the end the problem was very confusing. I had Version A of the DLL in which the error occurred. I upgraded to the latest version (B) and it still occurred. The guy at Resco sent me a DLL with debug strings being sent to the IDE (C.DEBUG) and everything worked. I reverted to Version B and now it worked whereas before it didn't. Don't you just hate phantom bugs that "fix" themselves?
In the end the Resco guy sent me a full build of the very latest code base (Version C) and all seems fine.
Both of us were at a complete loss, but thanks to their excellent support the problem with my application was kept to as short a time as possible!