Strange hydrometer readings

Hi all,
I was wondering if any of you have ever experienced this and what your thoughts are about this:

I was checking the gravity of one of my beers recently right before racking into secondary, just dropped the hydrometer into primary bucket, waited a minute for it to stop bobbing, when I looked at the hydrometer for a reading it slowly started to rise. It first read 1.005 then slowly rose to 1.008. I was using a finishing hydrometer (.980 - 1.020) @ 60*F. My temp was about 78*. I know that there needs to be a temp correction and all, but I thought this to be a bit odd. Thanks in advance.

Cheers, Kev

I'd be willing to bet the bobbing is due to CO2 bubbles stuck on the hydrometer. A little trick to ensure nothing clings on is to give the hydrometer a good spin. When you drop it in next let it settle to where the FG is going to be and then just spin it like a top.

Hope that helps

I failed to mention that is what I usually do. As I drop the hydrometer into the beer I give it a twist. So it is already spinning. That way I don't have to wait too long to take my readings. This has only happened to me a few times in 15 yrs. of brewing and only when I am about to rack into secondary. It is not a big deal to me, though I am curious as to what causes this. I am new to this (and any other) forum and thought someone else may have had a similar experience. Thank you for your input.
Cheers, Kev