Thanks for the link Unfortunatly it seems to be a bit more difficult. I ll try to explain why: If i use IOTA Light Wallet 2.3.0 and log in with my longer than 81 chars seed i get the expected balance. But if i use only the first 81 chars i see a zero balance.
Is it possible that there are two different seeds? If i follow instructions and use IOTA Light Wallet 2.4.0 with only first 81 chars of my seed i get zero balance when doing the transition search, so it would be plausible that two seeds are involved.