hello there , this is very common Qs among the adsl connection user,
I had the same problem when i switch to adsl connection this is what i found.
Yes In most of the cases it is normal for adsl connection to have slow upload speed because the isp assumes that most users send downloading req more (browsing) than uploading and isp have to send both voice signal for telephone and internet signal in the same line with fix bandwidth.
I have 2 mb/s bsnl broadband connection where my downloading speed is 200kb/s but uploading is only 50-60 kb/s.
hope this helps