I highly doubt it will be a problem. I never registered my visa (for a month) the first time I was in Russia (paid one 1000 rub fine when I tried to register it -- we don't do that at this office, blah blah). Wasn't an issue last summer (2000 rub fine this time though, for registering 2 hours late).
QUOTE(MarkandLada @ Jun 9 2008, 12:03 PM)

Hey all, as I am getting ever so closer to going to pick up my fiancee, I had a troublesome thought. I had my Russian visa registered as per procedure, but as I went to leave Volgograd I did not have it with me. Well, we had it with us, but didn't know it. Anyway, I had to go to this little office, sign a form, then I was allowed to leave. I am now applying for my next visa, and is this going to come back and bite me in the butt? I am planning to go on 7/9.