Importing freezes browser

I am importing 1000 accounts through Firefox.
While it is importing (which works), SuiteCRM tabs in my browser freeze up.
Other people work just fine and I can open Internet Explorer and it works fine as well.
Opening another FireFox browser on tha machine also spinns round and round incessantly for SuiteCRM but other web sites are OK.

Any idea why this is so?

Cheers
David

Very difficult to diagnose … there are so many factors such as browser versions, plugins and extension used in browser, operating system etc.

So, sorry, no simple answer, just more questions.