That would be news to me as I just used Scottrade yesterday to buy Edig. It is not on their list of restricted stocks (see their site link "Scottrade Messages.) I am using a cash account.
However, if you are using Money Direct Deposits, this is what they state on the site:
*The dollar amount labeled Money Direct Deposits* represents uncleared deposits made through Money Direct within the last 3 business days.
*Money Direct funds cannot be used to purchase stocks under $4, any unlisted stock or any options until the third business day after the deposit. Scottrade reserves the right to impose further purchase restrictions on these funds.