Webpages disappear off bottom toolbar

I had to reset my Internet Options under the Tools section the other day and since then when I open a new webpage, instead of the new page being shown along the bottom toolbar it over-writes one of the ones that are already there.
To get a new webpage I usually right click on the page that is open and open the Internet Explorer option, when my homepage appears. Then I type in the web address I want, ie gmail.com and instead of having 3 webpages on the bottom bar, I end up with 2. The same happens if I use google.com.au, and click on one of the links, one of my open pages is overwritten. It is most annoying as I used to be able to keep several pages open at the same time. It could be that one of the settings in the Tools, Internet Options, Advanced settings has changed and I am afraid I don't know who to get it back to the way I used it. BTW I do not like having tabs left open at the top of the page so have disabled that option.
Can anyone help me please.