Not so true anymore depending on the version you are running:
Beginning with MySQL 4.1.2, you have more flexible control over when a
+utomatic TIMESTAMP initialization and updating occur and which column
+ should have those behaviors:
You can assign the current timestamp as the default value and the auto
+-update value, as before. But now it is possible to have just one aut
+omatic behavior or the other, or neither of them.
You can specify which TIMESTAMP column to automatically initialize or
+update to the current date and time. This no longer need be the first
+ TIMESTAMP column.
The following discussion describes the revised syntax and behavior. No
+te that this information applies only to TIMESTAMP columns for tables
+ not created with MAXDB mode enabled. As noted earlier in this sectio
+n, MAXDB mode causes columns to be created as DATETIME columns.
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... more info at: MySQL doc page.