Using PUTTY and changes to the WINSCP temporary session

Today I've installed the latest version of Winscp after using the version 3 version for a long time. I have some Linux-servers that I support from my desktop and I let Winscp start a PUTTY-session for me.
I've customised the 'WINSCP temporary session' saved session profile for my needs, amongst others the size of the window and the character set for translation.
The new version 4 does not use the values that I've saved in the profile. Even worse, Winscp changes these settings. After starting Putty from Winscp the size of the window is reset to 80*60 and the characterset is set to ISO-8859-1:1998 (Latin-1, West Europe).
What is wrong here ? Is it a bug or did I do something wrong ? I have copied the 'old' WINSCP3.INI file as WINSCP.INI in the 'new' directory, can that be causing the problem ?
Thanks for any help.

I don't know why, but the settings of the 'default session' in PUTTY were changed (maybe because I also installed a new version of PUTTY). And I erronuously assumed that I should change the settings for the 'WINSCP temporary session'. But now, after changing the 'default session' in PUTTY the way I want it, everything works fine again. And this way I found out that the 'WINSCP temporary session' is build again from the 'default' everytime I start a session from WINSCP.

Before version 4.0.5, WinSCP would take temporary session as is (if it exists already), overwriting only the parameters WinSCP is aware of (hence keeping display options untouched).
Since 4.0.5, WinSCP first makes copy of default putty session and then it overwrites the known parameters.