Database Query timing and count is always disabled

luthien,

this setting is managed by the devel module as stated in the description of the field:

Log database query timing and query count for each page. This is useful to know if the bottleneck is in excessive database query counts, or the time required to execute those queries is high. Enabling this will incurr some memory overhead as query times and the actual query strings are cached in memory as arrays for each page, hence skewing the overall page memory reported. Please note that this setting is enabled or disabled in the settings of the devel module.

Maybe I should put the last line in bold in the module as well...

;-)

Edit: strong tags added to field description, available when there is a release.