PS2 Backups are very inconsistent

[gerryy]

I am having a great deal of difficulty getting backups to work on my PS2. I have a NTSC Version 4 with neo 2.0 modchip installed by a chipper and use GS 1.4. I have a Plextor 1210A burner and mainly use CDRWin and Nero to copy. I have used numerous types of media including Kodak, Verbatim, Memorex silver and black, Sony, TDK, etc. and I can't seem to get any consistency. My games will boot sometimes and progress to various screens but will always freeze at some point. I heard that if they will boot, they should work??
I have heard that version 4 PS2s do not play backups well, certainly not like the older versions (1,2 & 3). If I would have done more reading before buying the PS2 I would have made certain I had an older one ..too late now though.

Is it true that the version 4's do not play backups well. Would a newer modchip help? Should I use a different type of media? I am getting very frustrated with this situation.