Windows 7: How To Make Firefox Open Bookmarks Category Menus to One Side Only

Using a bookmark icon placed between the "address" and the "search engine" bars.
When I move the cursor down the bookmarks, one category will open to the left, one to the right, left, right, left right.............I would like them ALL to open to one side or the other.
Any suggestions ??

there are two bookmark icons one has a dropdown arrow, i guess this is the one you have , right click the top of firefox and select customise, in the window that opens then find the other bookmark icon and drag it to where you like on the ff toolbar ,you can also move any other icon to where you want in the toolbar.

alternately, go to view / sidebar/ bookmarks

You are correct. I'm using the dropdown arrow version. I know this is mickey mouse,
but when I click on the bookmarks there are several self-made cateogries, such as, "Computer, Media, Misc, E-Mail", etc. When I cursor over "Computer" all the URLs open to the left. Next category "Media" all open to the right. Third category might also open to the right, Fourth may open to the left. I would just like them ALL to open one way or the other. I know, I know, mickey mouse. Sorry about being so anal.

if you use my method to get the sidebar showing ,(on mine its the left) then click the tree to get your folders showing ,
, there are three categories, bookmarks toolbar, bookmarks menu and unsorted bookmarks. expanding the tree you will see the folders for your bookmarks computer ,media etc
on clicking them they will open down without opening a list to the left or right. its difficult to explain ,once you try it you will see its easy ,then by clicking the other bookmark icon i told you about ,it will open the and close the sidebar as you need it, mine is permanently open.

Generally, subfolders in the bookmark list will open to the right unless there isn't enough room to display the entire width of the current subfolder. Then they open to the left.

The only way to work around this is by editing the bookmark entries manually and shortening their names - each subfolder's width is determined by the longest bookmark name contained in it.

Alternatively you could rearrange your buttons and move the bookmark button further to the left, so there will be more screen space to open all of your bookmarks and subfolders to the right.

Appreciate all the replies. I did shorten up all the menu names. It helped although I still can't get the bookmark icon where I want it and have all the menu items open to the same side. No matter. Now, they all open to the left which works for me.
Thanks, again for your time.