Negatie input, breads negative results ... .
Prior to MS purchase of Skype: I used two versions. One Linux(Ubuntu); the other MS(Windows 7). After MS Purchased: When I added a new contact in Linux, which is working; this same contact was not present in MS. Using the recipricating method; I am able to add a contact in MS, and havevisible in the Linux version (Skype 2.2 (Beta)).
The fore mentioned version of Skype might have been 'open sourced' at one time (Pre-MS Sale). This is not the argument: Skype is now a MS subsidiary. Running from WINE has 'layering' issue that make the application inoperable. Skype is now proprietary software.
Using 'xmpp' is a starting point. At present: 'Pigeon Internet Messaging (PIM)' will allow activation Skype 2.2 (Beta). Only the (Beta) application runs independently; seperate from (PIM). This (Beta) mod must have been developed at a time prior to MS purchase; the newer versions of MS Skype only accept 'grandfathered' contact lists, for the (Beta). At present: New contacts created in MS Skype are operable from the (Beta). This too may change.
Because MSN in PIM is available; AND (Beta) as a seperate executable - It stands to reason that MSN may become inoperable, in the future. Maybe, that is the original purpose for the MS purchase of Skype? To exclude MSN from PIM like application.
Constructive evaluation of the issue will aid in a progressive path for resolution. Negatie input, breads negative results; AND only looses trackion towards the agreed on goal.
What is that goal? I do not know; however, getting there is not following the 'path of least resistance'.