calendar sync changes tmp files

A large number of .tmp files are building up in my folder Calendar Sync Changes. What I have done so far

1. Reset sync (http://support.apple.com/kb/TS1627)

2. Advance reset (http://support.apple.com/kb/ts2481)

I am using OSX 10.8.4.

The problem is probably due to the syncing between apple caledars and my exchange caledar. Anuy ideas ?

The .tmp files says

<?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>modified</key>

<dict>

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

<array>

<string>ExchangeCalendar/p7</string>

</array>

</dict>

</dict>

</plist>