reismarktq2 - I'm really not sure why that wouldn't work... Most of the code there was taken from the postbit section for the flags hack, so it
should work. I checked one of the flags in your postbit section and it was working fine and did contain %20 in the url, so perhaps it's something else? If you can't figure it out, if you could post the url that the image is pointing to I will try to help you figure out the problem.
ivanmcp - Checked and replied.

I'll try to re-write the calendar section for the hack as soon as I get the time. It does at least work properly if someone hasn't changed their "Start of the week" in their profile, so at least it shouldn't affect too many people. Re-writing the calendar part will require a bit of work and these last couple of weeks have been very busy for me. Hopefully though the next couple won't be quite as bad and I'll have the time to re-write the calendar, but unfortunatly I can't make any promises.
spick - I'm assuming you mean the URL for your header images and such is pointing to /images/ instead of /forum/images? If so then you need to modify your images path for each style you have as instructed in the install file.