Yes, the logo file is in the zip, but there is no reference to it from other files. I don't know how to add the logo to section 2 in checkout process and I don't have the time to hack this.

Just tested with IE7 and saw no problem with the return page. Maybe related to fact that the order is not created. Fix this first then check again with IE7.

The only improvements I can see in OSC 3.2 module is the key returning all the currencies instead of only swiss. In 3.3 version, there is a modification to follow a change by postfinance in the hash key, but this only affects recently registered users.

Anyway, I have modified version of the zencart module which addresses all this and which I should soon publish.