playing SU against AI (SU=100%, Axis=125%), I shipped some division to Hanko. The Finns retreated; after a while I started moving around and finally got to Helsinki, defended by a brigade. Next turn AI moved the brigade out of Helsinki, which I took. Resulted in Finland surrender in turn 10. I think that there may be some AI issue there - Finland should defend Helsinki, not move the unit out of it (also, they should contain me in Hanko)
If you need relevant saves, please let me know (which ones and the address) and I will send it to you.