repEEt problems

I’m working on a site that includes an event calendar as a major feature. Many, if not most, of the events repeat on a regular basis and I’m trying to get repEEt working correctly. I’m running into a few problems that I can’t get around:

1 Events that repeat have the following errors displayed in the header:

Notice: Undefined variable: date_separator in /home/ryeli0/public_html/EE/plugins/pi.repeet.php on line 389

Warning: explode() [function.explode]: Empty delimiter. in /home/ryeli0/public_html/EE/plugins/pi.repeet.php on line 389

2. Events that should repeat on a specific day of the month (e.g. first tuesday) don’t. I have tried changing the language file and drop-down selection list but no joy. Neither of these seem to work:

'first selected day of the month' =>
"first this day of the month",

'first selected day of the month' =>
"these relative days: first",

I’m using repEEt 1.0.7. Backreving to 1.0.3 seems to ‘fix’ the undefined variable errors but causes other problems.

I would much rather setup a calendar within EE, rather than using a stand-alone system, so any help getting repEEt working would ge GREATLY appreciated!