another tomato problem

I usually dont have a problem growing toms from seed but this year hubby has requested the large marmalade type we used to get in greece nice and fleshy but are they difficult to grow from seed as most of my attempts have withered ive now put in the last of the pack of said seeds hoping .
chrissie b

Are they withered or twisted? Greenfly can so that to seedling toms I found to my horror this morning.

What variety are they?

Are they too wet? I had a problem one year when my seeds got too wet and the roots rotted off but the external symptoms were that the leaves died off.

Do you mean Marmande? 

Ha i thouht it was marmalde as i have allways called them that , i havent the packet but will check when i go next to wilkinsons but they are the big ones with ridges .
chrissie b