I've also had problems with this account and again nothing in the literature but I think mine was covered in faqs no 35. As if you are going to look in there each time you want money in or out

When I tried they stated the only way was to use the CHAPs transfer feature charging £20. In addidtion to allowing larger sum transfer, this was also supposed to guarentee movement on that day which of course didnt happen. In fairness to ICICI they admitted it was their problem and are supposed to be reimbursing the CHAPs fee, although I am still waiting for it.
I have never had these sort of issues with ING.

Just to clarify that you can make multiple £10,000 withdrawals on the same day - thus allowing larger sums to be withdrawn. I have used this and it works OK.

Please be aware when using the ICICI HiSave account as they only let you move sums of no more than £10,000 back to your linked account at any one time.
This is not shown anywhere obvious in the opening webpage on their site, infact you have to go into their FAQ's and scroll all the way down to number 53 to find any information on this.
rgds