Posibility for speculative arbitrage with Penn West

Yahoo and other services inform us, that Penn West (PWE:NYSE, PWT.UN:TO) will buy Reece Energy Exploration Corp (RXR:V)
http://biz.yahoo.com/prnews/090310/to443.html?.v=3

According to the agreement, RXR:V owners will receive 0.125 PWT.UN:TO. With other words, for every 8 shares of RXR:V , 1 unit (share) of PWT.UN:TO will be received.

Currently RXR:V is priced 1.16 CAD. PWT.UN:TO is 9.92 CAD.

Simple calculation 1.16 * 8 = 9.28 , against 9.92 or 7% cheaper. [1]

There is of cource a catch. PWT.UN:TO gives monthly dividend, currently 0.23 CAD. The tax on the dividend, at least what I pay is 11%. this means from these 23 cents, i will receive only 21.
These 0.21 CAD real dividend against PWT.UN:TO 9.92 CAD is 2.11 %.

The buyout will be done "early May 2009". This means, if you choose to do so, you will "miss" the dividend for March, April and probably for May.

About May dividend, it will be (probably) received for shares on record on ~26.May, so probably the dividend for May will not be lost.

So back to dividend percentage 3 mo * 2.11% = 6.33%. This is quite close to the 7% in [1].

However I watched closely the ratio between those two stocks today and in one moment, the difference was more than 10%. I believe it will pay off to warch very close this development, and if difference go to 20% or more to add RXR:V, and probably sell PWT.UN:TO or PWE:NYSE as a hedge.

What the risk are?
1. What if the deal is broken? Then RXR:V will fall to the levels of 0.90 CAD. I do not believe this will happen.
2. The risk is the PWT.UN:TO or PWE:NYSE to fall in price. This will lead immediately to fall in price of RXR:V.
3. USD/CAD currency risk - there is NO currency risk, because once you buy the stock/unit, you no longer have money, and the stock/unit float in both USD and CAD.

NOTES:
1. RXR:V and PWT.UN:TO are traded on Canadian stock exchanges, and must not be confused with shares with similar tickers.
2. On some websites like Yahoo Finance, PWT.UN:TO is "transcribed" like PWT-UN or PWT-U
3. Nothing here in this post can not be viewed like trading advice or solicitation of buying or selling stocks.