I have also experienced this with my DoL and the Prospect/Triangulate abilities among others. The recast timer starts at around 21 seconds rather than 30 seconds. If I try to use the ability after the recast timer has reset but before the full 30s has elapsed, I get a "please try again later" message.
Logging off and logging back on did NOT solve this issue for me. Restarting the client DID.

Platform: Windows 7

ISP: TPG (Australia)

Type of Internet Connection: ADSL2+

Internet Connection Speed: 12Mbps

Date & Time: Cannot recall exactly, but would have been close to August 22nd.

Area and Coordinates: Treespeak, Humblehearth and other various areas throughout the Black Shroud.