I have posted this one to Coinpeople.com too, but I figured some of you might either be interested or know about this, so I'll post this here too :)
Just yesterday, I was updating my Soviet Union coin Excel-sheet and went through my coins, mainly to check that my Excel-sheet corresponds to reality. Especially late SU coins, with their mint marks were my concern. While doing this, I noticed that my 1991 5 Rouble coin, with oval-shaped "LMD" mint mark was a bit odd looking. It took me a little while to figure it out, but then I realized: the obverse and reverse sides are not properly aligned when compared to each other. If it is considered that the obverse side is 'fixed', then the reverse side (denomination side) is rotated approximately 10-degrees clockwise!
What do you think: is this coin a true error coin, or if this is just a result of poor quality control and thus, common issue. On the other hand, I couldn't find similar 'error' in any other SU coins that I have (I went through app. 400 coins yesteray evening) :)
-JJ-