Survey was not found or it is not withing validity period

Dear gurues,

Hope you can help me with this issue in CRM 5.0

I have created one survey, it includes dynamic questions by using function modules PBO and PAI, and fortunately it works fine when testing in trx. CRM_SURVEY_SUITE.

Now i am trying to generate a URL by BSP. It works almost fine, but for some weird reason, once I type "Yes" or "No" for the first question of my survey (next questions depend on the answer of first one, if "Yes" - second question should be shown, if "No" - second question should be hidden), and then click enter, I get the following system message:

survey was not found or it is not within validty period.

I have already maintained the validity period under maintain survey attributes in trx. CRM_SURVEY_SUITE.

the idea is to use this survey in e-mail campaign.

i will really appreciate your input

Thanks

Karina