I'd been having a few weird issues when loading Portfolios on to our Wealthz theme.
What was happing is after a certain amount when I was adding a new item then the oldest Portfolio would not show. After changing the category layout I was still getting some weird behavior in that the last 2 categories had all the same images.
The fix here is in the Wealthz theme options - go to
Theme Options, On portfolio options tab, number of portfolios will be a default of 12 . Change this to a much higher number.