CompareDate doesn't return and value

[Mai Morag]

Hey,
I'm trying to add to my dashboard 3 gadgets of Resolution Time  with 3 different filters:
1. Number of bugs that were resolved in less than 1 week.
The filter I tried:
issueFunction in dateCompare("", "created +1w >= resolutionDate ") AND filter = 42840

2. Number of bugs that were resolved 1 week -1 month

issueFunction in dateCompare("", "created +4w <= resolutionDate ") AND issueFunction in dateCompare("", "created +1w > resolutionDate ") AND filter = 42840

3. Number of bugs that were resolved more than 1 month

issueFunction in dateCompare("", "created +4w <= resolutionDate ") AND filter = 42840.

my question is- why doesn't it show results? sometimes it does but most of the time I get "No Data Available"?

** note: filter 42840 is a working filer by project and issue type that returns results