Signature verification

Today I spent a few hours trying to 'verify' my signature for an insurance claim. I often seem to have this problem - a government, bank or insurance officer wants me to sign something so they can compare my signature to the original they have on record. Although it looks the same to me, they often seem to find some fault and I end up having to repeat my signature 4 or 5 times. 

I then think the business is all finished, only to get a call later in the day that the supervisor is not satisfied with my signature and to come back in. Four or five tries later and the supervisor is satisfied. The next day I have to come in again because the head office is not satisfied...

Anyway, does anyone else have this little annoyance, or it just me? I've never had any problems like this in Australia.