Contacts is very slow, receiving txt message freezes phone

[tahlsr]

Hi,
I did a search under slow contacts and couldn't find anything. I'm hoping at the least someone will chime in stating they are having this same issue. Basically I have over 2,000 contacts and when I try to load the contacts it takes over 10 seconds. In fact because of so many contacts, even things like writing a text message where it does a 'type ahead' on my contact list can be extremely annoying and time consuming.

I also have this issue that if anyone sends me a text message, my phone will basically freeze for around 10 seconds (the backlight will come on and then nothing will work for 10 secs) and then the audible notification and icon showing a new text message will appear and the phone will be fine again. My suspicion is that it may be trying to match up the incoming phone number against my contact list.

Both of these issues only seem to occur after I synch with all my contacts.
After a nice hard reset with the latest rom, these issues are not apparent. It just seems like WM5 doesn't handle a large list of contacts (no good for business users) very well at all.

Does anyone else have these issues and can shoot me some sympathy? Is there any way to index my contacts or something at boot up? Also, can anyone state if WM6 fixes/increases the 'contacts performance'?