Well, you get what you pay for, though I must say it doesn't give (from an outside perspective) a good impression when it happens. My last bug report for a crash even had a minidump, which I thought might get it some attention, but there were no follow-ups. IMHO it puts ppl off, and I figure I'm wasting my time.
See Chapter 12 Troubleshooting in your VirtualBox users guide. Although they may not have assigned this there are other reports that indicate various issues with the clipboard. I can almost promise you that the DEVs will ignore a bug report with no guests log file since all they will have to go on is this does not work.