In the DRAFT Guide to Financial Issues relating to FP7 Indirect Actions Version 24/4/2007, it states on page 21:
"After approval of the periodic reports interim payments will follow and will be calculated on the basis of the accepted eligible costs and the corresponding reimbursement rates as indicated in Article II.16 of ECGA. The amounts paid for interim payments will correspond to the accepted EC contribution. However, the total amount of interim payments + pre-financing will be limited to 90% of the maximum EC contribution. This may imply, as mentioned in the examples below that in some cases payment for the interim periods may be reduced in order to respect this limit."
This is much better than was the case in FP6 - it essentially returns to the situation of FP5.