Search engine help on Firefox

I’m having trouble using search engines. Every time i search something, the results show up, but then, when i click a link, it keeps going to some next random sites, and whilst the page is loading it says Jumping on the Tab Bar, before redirecting me to the different sites.
Can any1 help?
Im using Firefox 3.5 Beta 4
an example when choosing a link from google is http://selectorweb.net/?q=hshs will show up, whilst directing me to a site like http://www.britanniasearch.co.uk/search.asp?q=hshs or
http://music.myspace.com/index.cfm?fuseaction=music&utm_source=Mva&utm_medium=cpc&utm_term=mus1&utm_content=mus&utm_campaign=mrc
i started using Yahoo instead, and it worked fine, but it has now started doing the same thing:(
Answer #1
in the firefox adress bar enter about:config in the earch filer find , default search engines and modify as required , that or choose to open firefox safe mode , when prompted choose to reset all the values , including default search engines , keep your bookmarks if required , if it persists after that download and install malware bytes and see what it comes up with ,