User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-GB; rv:126.96.36.199) Gecko/2008070208 Firefox/3.0.1 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-GB; rv:188.8.131.52) Gecko/2008070208 Firefox/3.0.1 Sorry for the summary, but I can't think of a quick way of describing this issue. In FF 3.0.1, if I do Tools > Show all History, and then I want to resize the 'name' column to expand to the size of the largest entry, I would normally expect to be able to double-click on the edge of the column's header, which would automatically resize the column to fit the largest entry. However in Firefox, it counts as double-clicking on the selected entry (the default being the highest in the list). Reproducible: Always Steps to Reproduce: 1. Tools > Show all History 2. Point mouse pointer between 'Name' and 'tags' column, so the pointer changes to a resize pointer. 3. Without moving the pointer, double-click. Website opens unexpectedly.