problem faxing with Dell AIO 946

I've had a problem with faxing since I bought my desktop and AOI printer but don't need to fax often and finally getting around to asking for help. First of all, when I discovered the problem shortly after setting it up I called Dell CS and they said I would have to unplug my telephone because of the answering machine. I had a Lexmark before the Dell and I never had to unplug anything with the Lexmark, so there has to be a better way with all the technology out there.  I should mention I'm using one phone line with DSL filter for phone and a 3-plug adapter for additional equipment, but nothing stays plugged in all the time (when I had the Lexmark I could keep it plugged in all the time but can't do that with the Dell 946).  Anytime I have to fax something, I have to unplug my telephone and then I have to crawl under my desk and plug in the line from the printer into the telephone jack.  Just about everytime I need to fax something I cannot do it using the AOI Center software and have to use the keypad and manually punch in the fax#.  However, there have been times in the past I was able to fax using the software and I don't know if I was doing something differently then and just forgot what that was, or if something has changed. I rarely receive faxes, but the times that I have, it seems like I recall increasing the number of rings in the AIO Center and then the answering machine would not pick up and the fax came through.  I should mention that I have no trouble using 'scan and email' option via the AIO Center.  Any help would be much appreciated.  My knees just can't handle crawling under the desk everytime I need to fax.  Have a great day!