Not sure which version of LR you have, but in LR3 for example, pressing the '\' key brings up the filter bar in the library module. You can select from Text, Attribute, Metadata or None for filters. There's also a 'lock' icon that will make filters sticky (or not) across folders. Click 'None' to remove all filters.
Go to all photographs and the edited tiffs are there as number 1 of 2 next to the original raw file. I thought perhaps that they hadn't inherited the original keyword from the raw file so I select them and drag them to the keyword and this doesn't increase in size - i.e. the new tiffs are already keyworded correctly
In the Library module, right panel, second box down is 'Keywording'. Select an image or a group of images and the keyword(s) associated with that image or images are shown in the box. Have you looked to see what keywords are actually there? BTW, if you have more than one image selected, any keyword shown with a '*' beside it means that keyword is present in only some of the images selected.
Mike.