custom views / macros

In creating a custom view from a master document, I manually hid every third
row for 1000 rows (whew), assigned a custom view name, added a macro to to
show only a particular heading for that view, and assigned a shortcut
(cntrl-L). The worksheet was saved as a template. The file was then resaved
with a new name and cells filled with desired info. Pressing cntrl-L worked a
few times, then suddenly, the view no longer had every third row hidden,
though the heading macro still worked.

1. I don't know why it suddenly stopped working and

2. can you help me write a macro that hides every 3rd row automatically?