Tax error when add product option

When I add product option with my product the price incl. tax isn’t right.



If there aren’t any product options with my product, the calcullation of the vat is good. (100 euro excl. tax will be 121 euro incl. tax 21%)

But when I add for example 3 options (options are for free) (100 euro excl. tax will be 221 incl. tax 21%)

Like you can see he add 100 euro



I used 1.3.5 SP1

Before this version there where no problems with this