Hi Sarma,
Thanks for your reply. I found that the problem was not with the programmer but with the 16F88 I was trying to program.
Unfortunately I only worked this out after I had bought an ICD2.5USB programmer. Anyway I like the new programmer and the old one still works fine and your suggestion about servicing the old one is a very good suggestion if I hae trouble again or for anyone less hasty than me.
Regards, Mike