Zip/Post Codes

Hi All

Just starting to test 2.04 prior to migration and have found a possible bug in shipping estimator

We have set up a custom shipping method exactly as in 1.3.5 (which works fine), delivery cost varies dependant on post code.

We use post codes starting TS1 thro TS27, TS1-TS8 are one cost, the remainder have a higher delivery charge. We have used wild cards, ie TS1* TS17*

The problem we have is if the customer puts TS17 it sees TS1* and therefore gives the cheaper delivery charge, It seems the wildcard is not working correctly.

Has anyone come across this and any idea how to rectify.