From the WinUAE website [Click read more to see]

WinUAE 1.3.4 (30.12.2006)
=========================

Bugs fixed:

- Improved bsdsocket emulation stability
- Winuaeclipboard crash fix
- Windows Vista compatibility problems fixed
- Filesystem flag handling on FAT volumes
- Page Down-key Input panel remapping works properly
- Sound system improved
- ECS Denise/AGA borderblank feature works properly
- Dualcore/SMP random freezes properly fixed

and more minor fixes..

Bugs introduced in 1.3.3 fixed:

- AVIOutput out of sync fix
- CPU emulation condition code fix
- Fixed handle leak in bsdsocket and AHI
- Sound pitch shifting in VSync-mode and more..
- Catweasel MK4 mouse support

New features:

- Improved emulation of AGA sprites outside display window
- uaeserial.device introduced. Multi-port serial device, unit numbers
are directly mapped to PC serial ports (unit 0 = COM0, 1 = COM1 etc..)
- Improved serial port detection, virtual devices also supported
- Improved Catweasel MK3/4 support without Windows driver installed
(requires TVicPort, http://www.entechtaiwan.com/dev/port/index.shtm)
- Improved debugger features
- Sound system is not anymore reinitialized when losing/gaining focus
- 1M (1024KB) ROM image support
- Sound volume configuration setting also sets AHI audio volume
(previously was Paula audio only)
- Custom chipset interrupt timing improved

And more.