Microsoft has released ActiveSync 4.5 Beta 2 which boasts better stability and less connectivity problems:
Changes in ActiveSync 4.5 Beta 2 help resolve issues related to setup, partnerships, and connectivity with the PC and Microsoft Exchange. In addition, it includes a troubleshooter utility that scans your computer and device to identify problems and offers information and corrective actions to solve them.
ActiveSync 4.5 Beta 2 supports PC sync via USB cable, Bluetooth, or infrared connection.
I still won’t be making the upgrade because Microsoft removed wireless support after ActiveSync 3.8. It is so much nicer being able to wirelessly connect my Pocket PC and my desktop computer rather than having to wire them up together. I mean come on, everything is going wireless these days and if they were having problems with it they should have figured out a solution instead of scrapping the feature all together. HPC Factor still lets you download ActiveSync 3.8 if you decide you want the wireless feature.
In case you were wondering why exactly the wireless was removed here is what they say:
Remote PC Sync (via WiFi or LAN) has been removed due to Enterprise customer feedback around security issues.
So why not just provide an Enterprise version of ActiveSync that doesn’t have this feature? Sorry, I’m a little bitter over the whole thing if you can’t tell. 
I agree with you, they should have made an enterprise version without it and left wireless for the masses.
The company I work for really hates wifi for security aspects. However, they like to make a blanket statement and say it can’t be used at all. Instead, they should allow it for use for non sensitive operations.
Now for our maintenance side, we need it and they are going to allow it, but it has to be on it’s own subnet with hardware firewall and no other systems can access it.
Yeah, wireless can be a pain in the corporate world because it is hard to contain/limit a signal yet make it available to the people who need it. And yet they are starting to cover entire cities with it.