Puzzling problems with printing and scanning in Trinity 3.5.13 with Slavko's repositories added.

Hi all! I have had the following cris de coeur from the user of a computer that I administer. "The old system" means Debian Lenny with KDE 3.5.10, which is still there on a separate partition and can be booted into from Grub. I had previously successfully installed Debian Squeeze with Trinity 3.5.12 on his wife's laptop without a problem, and it is running well, including printing and scanning. The installation for the wife was from scratch and there was nothing to restore. The husband had a lot to restore. The printer and scanner form part of an aio, a Lexmark Interact C605. The initial problem with the printer was that when I came to install it on a 64 bit system (Lenny had been 32 bit) I found that the driver was only available in a 32 bit version. I found a 64 bit driver - not on Lexmark's site, of course :-( - and all seemed to be well. The story carries on below in emails from the owner of the machines. I am baffled as to how a driver can work one minute and not the next. :-( I do hope that I haven't managed to install some sort of malware masquerading as a driver. 12/08/07 (yy/mm/dd) <quote> We still have some snags with the new system I'm afraid. 1)The scanner will not work although it still does in the old system so I know the scanner is working OK. 2)The printer works from e-mail OK except that it will not print attachments which are in PDF although I can read them aok. </quote> 12/08/16 <quote> The printer which was working aok in the new system (apart from pdf format)has now ceased to function completely again although it is working still in the old system. </quote> His wife can still print from her laptop. I had expected to find that the problem with the scanner was a matter of groups and permissions, but it would appear not; or anyhow, not entirely. Any suggestions for solutions, other than reinstall with 32 bit and Trinity 3.5.12, gratefully received. Though this is beginning to look like the only viable solution. I ought, of course, to have checked, before I abandoned 32 bit, that all the necessary drivers were available in 64 bit. :-( Thanks, Lisi