problems adding stock to an existing listing

[rocksoliddrums]

Hi - I need help with an existing listing which has two variations. I recently had to mark the stock level to zero on one of the variations because I was temporarily out of stock. I'm back in stock now but it is not letting me add the new stock amount available.  I have spoken to Ebay who were about as useful as an umbrella in a typhoon and in the end was told it is a glitch. That was last week and I've kust tried again to day and it is the same. Has anyone else experienced this and any tips on a way around it? I have created a new listing for the size but of course it doesn't have the sales history anf therefore the ranking as the original one.

This is the message in red which I get on the listing - 'It looks like there's a problem with this listing.

• Model is not allowed as a variation specific.'

Thanks.