I cannot confirm this issue. I had DNN 4.5.3 and Events 3.3.8 installed and just upgraded to DNN 4.5.4. Then I created a new event in weekly view, and it showed up. What exactly did you do?

Hi Matthias,

on what weekday is your event, and what language are you using in DNN? If the event is on a sunday, and your selected language is NOT English, then select the default language "English (US)" and check if the event is displayed then.

I think just reproduced your issue; at least I discovered a localization issue with the weekly view. The reason seems to be that in English locales the week starts on Sundays, wheras it starts on Mondays in most european countries. The monthly view and the event list are not affected by this.

Try this to reproduce the issue:

1. Go to a page with an Events module on it, and select "View Week".
2. Select "English (US)" as language.
3. Enter a new event on a sunday, e.g. on July, 22.
4. The event will be shown on Week 30 of Sunday, July 22, 2007. OK so far!
5. Now switch to a european language except of English. I did it with German (de-DE), but I think most other european languages will cause the same issue.
6. Result: now you're in Week 29 of Monday, July 16, 2007. You don't see your event because you're one week back. Still OK, but:
7. Go to the following week 30, but your event doesn't appear in this week either! (In fact, it doesn't appear in any week I checked from 27 to 33)
8. Switch back to English, and your event is back again.

So I think it has nothing to do with the current date, but only happens with Sunday events in non-english locales. Can you confirm this?   

[EDIT:]
The above happens with Events 3.3.8 on DNN 4.5.4. I couldn't reproduce it with Events 3.3.8 on DNN 4.3.6 and Events 3.3.7 on DNN 4.5.1