Open source is no bad thing.
I witnessed how much happier clients were to know their bug or the improvement they asked for was being managed in a coordinated fashion and they could be reassured with feedback when they wanted it. For example they would be given a clear indication as to whether their problem was being solved as part of a general upgrade, or that a patch or an upgrade was being developed to address their precise requirements. Hassling the developer who is, who has no relationship or obligation to your firm and isn't going to go that far out of their way to accomodate you if you've got slightly different requirements is no solution.