[TYPO3-calendar] Cal 1.4.0 and Typo3 4.5.2

[Marc]

Hello!

I try to install Cal 1.4.0 with T3 4.5.2.

After selecting in the Extension Manager the Upload extension File 
directly (.t3x) and selecting the file

	cal-1_4_0-dev-r3004.t3x

downloaded from

	http://svn.webempoweredchurch.org/snapshots/show/calendar
	(Thanks Thomas Kowtsch!)

I see a progress bar fueling up and down for a while. After that a blue 
window fades in saying "Extension null was installed" and the Extension 
Manager reloads. But Cal is still unavailable.

I tried both options (overwrite existing extension). The log-module did 
not report anything exceptional.

Previously there was Cal version 1.3.3 installed. I removed that version 
by hitting the "Remove Extension" Image.

Please: Has anyone experienced similar?

Best Regards,
Marc