I hate to say it, but look at the Trading Discussion forum. It looks like MtGox isn't doing so well, were are you located? Maybe it'd be better to do some local trading, or trading with a exchange that is more responsive.
We are doing just fine thank you very much!
On the MtGox GBP deposit page there is a polite notice stating that,
Direct cash deposits should not be made, as they may not be credited
Does this mean that they no longer accept cash deposits or is it just a warning that if you lodge cash there is a higher chance of error? I've deposited cash in the past and it all went smoothly. If you tell the cashier to input the transaction message I can't see what could go wrong.
As for GBP Cash Deposit, we have a small technical issue lately and that put us and our customers into a very delicate situation. The problem is simple some users either completely ignore the fact that their name is needed or they do not write correctly their Mt.Gox account number on the deposit slip, making it extremely difficult for us to know where the money is coming from.
The many mistakes we see is regarded users Mt.Gox account number that MUST BE WRITTEN as follow in CAPITAL LETTERS ONLY :
Now even if we still process some cash deposit we would like you to be very careful when doing so and would prefer you guys to use other methods until we sort this matter out.