25,000 British nationals visited Nepal in 2007 (source: Nepal Tourist Board). Most visits were trouble free. The main types of incident for which British nationals required consular assistance in Nepal in 2007 were: replacing lost and stolen passports; arrests, mainly drug-related; and hospitalisations, generally as a result of trekking accidents. You are strongly advised to use a reputable travel agent and only trek with an experienced guide and in a group.
For more, Richard, visit:
http://www.britishembassy.gov.uk/servlet/Front?pagename=OpenMarket/Xcelerate/ShowPage&c=Page&cid=1067968460507
It's just some will try to disrupt elections around 10 April - but I doubt you are an antagonistic person and would stay clear of crowds lol