I have exactly the same problem on my X50v
It appears to only happen after I run an application which uses .NET CF V2 (and some others...)
For example, the new WIFIFOFUM (WIFI scanner -
http://www.aspecto-software.com/xoops/) causes this problem for me.
After a soft reset, skype is OK.
This also happens with other applications, and is causes by others - not restricted to skype. But always on the Dell X50v...
Adrian