Hub one or replacement? Advice please!

[#1]

Hi!
We've had real problems with Plusnet hardware ever since it was installed.  The two main frustrations are:
1) the router connection drops out at roughly the same time every evening.  It comes back by itself 10-15 minutes later.  Everything running (including baby monitor) is unusable during this time.
2) the router does not allow me to manually allocate an IP address to specific machines.  I have never known a router without this basic capability!  Our wireless printer and linux box are pretty much unusable now.
Can anyone tell us whether the new Hub One is likely to fix these problems?
Or can anyone recommend a reasonably priced VDSL modem/wireless router that will work with Plusnet?
Many thanks!
Richard

[#2]

Two questions
Which router do you have
Do any of the lights in the modem change when it drops out
I use the Billion 8800NL and it works very well
If it is the 2704n then you can fix them via this link I believe http://192.168.1.254/expert_user.html

[#3]

Thank you!  As far as I can tell the openreach modem connection persists, it is the router that falls over (it never shows a long uptime).  But I haven't yet caught it to confirm.
It is a 2704N, I presume you mean fix by updating the firmware?  Is there a download image available?
Richard
[Moderator's note by Mike (Mav):  Full quote of preceding post removed, as per Forum Rule]

[#4]

Thank you again - I've just found a static IP lease link which I'm sure wasn't there when I first checked!
Much appreciated.