.tmp files in ~/Library/Calendars/Calendar Sync Changes?

Hi,

I noticed recently that huge numbers of .tmp files in:

~/Library/Calendars/Calendar Sync Changes?

were getting backed up. They have names like D2AAF5C6-0C3A-449E-8A59-0D8FBA29AA28.tmp. Last night when I looked in that folder, there were almost 370,000 of these files. While I have deleted them (it took a long time!) and have not noticed any adverse affects in iCal, I am noticing that something is generating 7 or 8 of these files every hour. Since last night, there are 118 of these files in there. Here is that the contents of one of these files looks like:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

<key>deleted</key>

<dict>

<key>com.apple.calendars.AudioAlarm</key>

<array>

<string>Alarm/p14689</string>

</array>

</dict>

<key>modified</key>

<dict>

<key>com.apple.calendars.AudioAlarm</key>

<array>

<string>Alarm/p14696</string>

</array>

<key>com.apple.calendars.Event</key>

<array>

<string>Event/p14508</string>

</array>

<key>com.apple.ical.calendars.DotMacPublisher</key>

<array>

<string>Publication/p1</string>

</array>

</dict>

</dict>

</plist>

I don't recall seeing this before (I am running OS X 10.7.3). Does anyone know what might be causing these files to be generated and what I can do to stop them from being generated? Finally, I should add that iCal feels much faster since deleting these numerous tmp files.

Thank you.