Where is the highlighting: in the bookmarks sidebar, on the bookmarks toolbar, or on the bookmarks menu?

Can you compare your add-ons on the two systems? In particular, if you call up Help > Troubleshooting Information on the two systems side by side, do you have any bookmark-related Extensions on your XP system that you haven't yet loaded on your Win7 system? (If the systems are too far apart, you probably can copy and paste that list of extensions from XP into email and email it to yourself to view on the Win7 system.)

The bookmark highlighting is on the sidebar. As far as BM extensions, both have JAVA Console plus the following:

    XA  -  Garmin Communicator & JAVA Quick Start (a few more disabled)

    W7 -  LivingPlay  TextLinks  (And one disabled)

I think that this is complete. I assume the disabled ones are not of concern.

If I squint very closely, I can see there is a bar of slightly different color behind the last-clicked bookmark on Firefox 5 / Windows 7, but the contrast is too low to see it at a glance. This could be because I'm using the "Basic" theme for Windows 7 rather than one of the fancy Aero themes.

What would you think of a little hacking to get more contrast, as in these images?

Here's how to get that. First, you need the Stylish add-on. It can override and tweak browser menu and toolbar settings, as well as tweaking styles in web pages.

Stylish :: Add-ons for Firefox

Next, set up this rule, which adds the blue shade behind the bookmarks list. You can edit the color later if you like.

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);
#bookmarks-view-children {
 background-color: #bdf !important;
}

How to do that? Once you install Stylish, you should see an "S" icon in a box on your Add-ons bar, with a little drop-marker triangle next to it.

1. Copy the above style rule to the clipboard.
2. Open the Bookmarks Sidebar and click a bookmark so one is selected.
3. Click the Stylish icon on the Add-ons Bar and choose Write new Style > Blank style.
4. Paste the rule text and click Preview. The effect should be immediate.
5. Name your new Stylish rule (I called mine Sidebar Contrast) and Save.

Any luck?

---

Extra Credit: To edit your rule after saving, for example to change the color, you normally have to go the Add-ons page and click Options. This is inconvenient for styling parts of the browser that do not appear on that page. You can manage your Stylish rules in a pop-up instead by changing a preference.

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the filter box, type or paste stylish and pause while the list is filtered

(3) Double-click extensions.stylish.manageView and change its value to 1 (the default is 0).

You're done with about:config and you can close that tab. Now when you choose Manage Styles from the Stylish icon, you'll get a pop-up in your current tab rather than changing to the Add-ons page.

Appreciate your suggestion. However, when I look W7 FireFox , I do not see any shading but just underlining. When the cursor moves off the underline disappears. So, at this point I will consider your suggestion and do a bit research. I have to close at this point but will continue tomorrow. Thanks

After trying several things, I have found a solution that is adequate for mi need (ie., somewhat close to FF5 in XP. Starting with a list of Bookmarks (BMs) in the left BM column, I select the first one. After the site has opened, I move the mouse pointer into the displayed frame and if needed I can open other pages. Looking at the BM list (ie., in the left vertical Bookmark frame), I have lost any indication of the selected BM. By moving the pointer to the vertical BM slider (separating the BMs from selected pages) the slider turns BLUE and then push the left mouse button and the last referenced BM becomes highlighted. Although this is not as nice as FF 5 in XP, I find it adequate for the FF 5 W7 environment. Thanks for your input.