Online Contribution Page ignores number of terms defined in membership price set

During an online contribution the system ignores the number of terms set in the memebership price set. Instead, it sticks to the default term of the membership which is set in the membership types section.

Example

We have a membership type defined with a term set to 1 month. In the price set, an option of subscribing for 6 months is listed (6 terms). Everything seems fine, however when payment goes through membersip end date is reset to be after one month, even though the contribution was made for 6 months.