I too am having the same problems: scrolling the map often freezes with "Parsing Geocaches..." notice, blue frame not snapped to new location, and "Error on Page" notice in IE's Status Bar (lower left). If I grab the map outside the blue frame, scrolling is highly accelerated and almost uncontrollable. Etc.
I am running:
Dell laptop @ 1.6/3.02 GHz , with Nvidia GEforce Go5200
XP Pro /w SP2 and current, IE7
I spent 30 minutes testing to see if I could find some clues the Groundspeak folks might use. Here are my results:
Deleting IE's temp files had no effect.
Not moving the mouse after releasing the mouse button does seem to help. Likewise, not scrolling very far at a time (less than half a frame) also seems to help. Scrolling slowly (not really slow, just smooth movement instead of quick jerks) also helps. Not letting go of the mouse button until after the (jerky) map has caught up to the cursor also helps. Being really patient for a frame that has over (say) 100 caches also helps. Using these techniques, my scrolling succeeds maybe 75%.
I'm running Norton Internet Security 2006 (which includes antivirus, firewall, intrusion, spyware, and phishing protections). This and Microsoft Defender are the only real-time security packages I run. I turned each of these protections off, one at a time, opened a new map, and tried to get a scroll to freeze. With the Auto Protect feature turned off (and only that feature), I could never get scrolling to freeze up, no matter how viciously I violated the above techniques. With Auto Protect turned on along with each of the other protection features turned off (one at a time), I always eventually got a freeze, although it might take me five or so tries. It's not consistent.
Norton Internet Security 2006's Auto Protect is clearly implicated (at least on my machine). It would be interesting to know if many of the others reporting this problem are also using a Norton security product (Notron provides the same bits of software in a variety of different packages). If not, have they ever had a Norton or Symantec security product on their machine (perhaps not completely removed). I'm sure the good Groundspeak folks would like to hear from everyone on this.
Be cool, and try to help.
dbir