Operating System: Mac OS X 10.4 (Tiger)
I have a table of which one column contains dates, in the format 4/19/09... except that some of the entries are blank, and some have a word or two in front of the date. I wanted to see only the ones that didn't have a word in front of the date, so I did a "custom filter" on that column: "begins with 4 or begins with 5" (since all the dates were in April or May). The last row showing in the remaining table looked like it had the right row number, but rows 2-30 were invisible: it just jumped from row 1 to row 31. I couldn't see the missing rows by "Go To... A24", nor by moving around with arrow keys, nor by scrolling. Eventually, I discovered that row 30 was zero-height, and I could expand it to normal height with the mouse... and then expand row 29 from zero height to normal height... and then row 28... and so on. I tried selecting the entire table and "Format->Row->Height->0.20", but that didn't affect the zero-height rows, and the only way I was able to see them was to expand them manually, one by one. Or I could "Show All", of course, but then I also got the rows I wasn't interested in.
The next time I tried the same filter, it zero-heighted even more rows -- around 40.