If the transfer was into your 07UY, then you can get another transfer into your 08UY, but those points can only be used for a reservation in the 08UY or banked into the 09UY. And because the points retain their original UY, this may give you the flexibility you need.
For example, say you are planning to travel in June, 2008 and have an Aug UY. You have already done your once a year transfer into 07. However, Feb, March and April UYs will use 08 points for a June 08 reservation. So you could get points tranferred from a member with any of those UYs for 08 and still use them for your June 08 reservation. You will have then also used up you 08UY transfer.
Best of luck -- Suzanne