Find not working

Hi
I have one spreadsheet on which Find not working (was working just fine). Seems to work in other spreadsheets.
VVV frustrating!
Any ideas?

Most of the cells in this spreadsheet are "general" some have text, others text & numbers - eg registration nos for vehicles & there are some Currency cells.

I am trying to find, in particular things in the format B111111 - formatted as general. This has always worked in the past (although the B must be there), but today, not working at all & I really need to find some of these numbers.
I have tested it with ones I know are there because I can see them, so it's not a case of the entry really not being there.

Any help greatly appreciated.
Win 7 64-bit pro, all updates (just updated to see if that fixed it)
Excel 2010 student
8GB RAM
Ta

Hi
Soon as I posted this, went back to Excel. Now working.....