Thank you all for your input. 'Cheesey' I agree with you that asking for a damage deposit 8 weeks in advance is OTT and a slow return of the deposit would also be unacceptable in my opinion. However, on behalf of owners of the properties that you pay over £1000 a week for, I would like to point out that these properties are obviously of a very nice standard, in order to give you a 'home from home' experience, and therefore if items in the property aren't treated with the appropriate respect and are damaged they are likely to cost a lot to replace or repair, which is why owners ask for damage deposits.
To 'Paddyann', you were obviously VERY unlucky with the owner of the property where you experienced an extremely raw deal, and I would certainly not even consider charging for the situation you have described.
Mamissimo - If you provide a high end property then that's exactly the reason why you need to take a damage deposit. For example if your property is at the lower end of the market, then replacement costs of cheap sheets, duvets etc, are bearable, but if you are paying out for top quality bedding and furnishings in order to give a memorable and luxurious holiday experience, and then it's treated with a total lack of respect, frequent paying out for replacements soon adds up.
'Lazygirl', owners are not able to claim tax relief for wear and tear anymore.
I would also like to explain that property owners expect 'wear and tear', and most wouldn't dream of charging for a broken glass or whatever, but damage caused by a sheer lack of respect is not only disappointing, but sometime can have a severe knock on effect, for example, imagine if you have someone who causes a flood through sheer lack of respect and carelessness, not only does it cost money, but also in some cases you only have 5 hours in which to get the damage sorted out for the next guests, and if it can't be sorted out in that time, then the owners bear the responsibility for paying out not only for the repairs and damage, but also for new accommodation for the incoming guests. So really our reasons for considering a damage deposit, are not so much to cover financial loss, as we do hold insurance for major problems, but more to encourage respect of the property and it's contents.