Banks - Whose Money Is It Anyway?

It's that time of year when the rental is due for our static van for the next 12 months. Building Society can't pay it direcly, so no problem, we'll get a cheque, pay it into our bank and then transfer it. Got the cheque, paid it in yesterday, checked our balance this morning, all seems OK so off I go to the bank to transfer the funds. Sorry, you haven't got sufficient funds in your account says the very nice lady in Nat West. Oh, but I got a balance this morning and it shows we have says I. When did you pay the money in she asks? Yesterday morning I reply. Oh, well that won't have cleared then even though it's showing on your balance she explains - I should leave it till about next Tuesday.

That's 1 whole week after I paid the money in. Absolutely ridiculous in this day and age I thought - anyone had a similar experience?