Whole post edited to reflect the fact that this wasnt a bug. Can probably delete this thread now.
On the Options>Plugins page, clicking the on/off icon to the right of the checkbox will change the icon but not enable or disable a plugin. (This was an incorrect assumption, it actually does enable/disable.)
This causes the "Running plugin" icon to change to the "Unloaded plugin" icon and back again. Pressing apply reverts the icons to their natural state (this requires checking and unchecking a checkbox to enable the apply button.) This only seems to happen with the indicator icon of certain plugins:
- Plugins whose on/off icon will change: avs, crashdumper, dbeditorpp, import, importtxt, pluginupdater, seenplugin, shelxt, spellchecker, tabsrmm, tipper, yamn
- Plugins whose on/off icon will not change: advaimg, dbchecker, dbx_mmap, historypp, icq, yahoo.