Version 1.2 of the Windows XP driver has a memory leak – the solution is to upgrade the driver to a later version of the driver.
Version 1.3 (driver date: 05/11/2009, driver version: 5.60.180.11) also appears to have a memory leak (this version appears to leak faster than v1.2).
(System: Windows XP 32-bit, Pentium 4)