The recuring problems I have is buying custom scripts from lazy programmers. Once they get their money, they no longer respond to e-mails or when they do, they start treating you like an imbecile.
I try to stay clear of custom scripts and get instead "over the counter" scripts even if it doesn't do 100% of what I want it for. At least, I know the script has been tested by numerous webmasters and bugs will be fixed quickly.
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