This isn't a Links SQL bug, but a server misconfiguration that has become more common in the past few months. If you attempt to modify a link or category, and always get the error: "The record you are attempting to modify has changed since you last accessed it." then there is a good chance your server is misconfigured.
The issue arises from MySQL not being able to compare date's properly due to your server being configured using the "/right/" timezone. The "/right/" timezone is meant to be used for exact time as it takes into account leap year seconds.
More information and details on fixing this problem can be found:
Gossamer Threads Inc.