i have a direct ISA issue 4 account opened last tax year with Alliance & Leicester. this year they have direct ISA issue 6. what is the difference between issue 4 and 6 and do i need to open a new account with an issue 6 or just put the money in the existing one with issue 4? i'm not to sure if the interest rate is the same or lower for issue 4 but seems ridiculous to open another account and transfer the money since it's the same bank
or is it better to open a normal savings account as it seems their rates are higher now than the ISAs?

Different issues tend to be different set rates. The big trap is that a new issue may offer a competitive savings rate for 12 months, and then drop to BoE rate modifier afterwards - which means many issues with different providers have awful interest rates, but many people don't realise it.