Remember, I told about a client where the webid jumped unexplicably? Another of my clients hit the same problem and he realized the exact sequence that led to it. I just reproduced it on a demo server. Add a web, enter everything necessary for creating, but use an *invalid* domain, for instance "this is not a domain"! Then save it. Next screen will show "Invalid domain name:", Weiter/Continue >> At this time the webid apparently is already incremented. If you now go thru the same process again and add a web with a "good" hostname, the webid will "jump". I reproduced it several times, just to be sure. I assume you already hit the table to get the increment value before the syntax check is done and fails the operation. Or some such. Should be easy to avoid that.