Incomplete map on GPS

[Durham Ranger]

I recently downloaded California Topo 2011 and transferred it to Garmin Base Camp successfully. However, when I download it to my Garmin Oregon 450, a portion of the map does not show up even though the same area shows up in Base Camp.
I have tried deleting the map and re-installing it in Base Camp and transferring it to my GPS several times but always with the same results.
The indication is that the problem is with the GPSr, but what the exact problem might be is beyond me.
Anybody have any suggestions or comments?

[jolly47roger]

Are there any other maps on the GPS that might have conflicting segment numbers?

JAVAWA GMTK can help to diagnose this

[Boyd]

Do you have additional maps installed on the GPS? There is an important limitation that many people are unaware of. Maps consist of smaller tiles called "segments", and newer Garmin handhelds typically have a limit of abouit 4000 segments (old units only allow about 2000).

This limit has nothing to do with the size of the map in megabytes, just the number of tiles it contains, and there are no standard sizes for tiles. The total segment count is the sum off all maps installed on the GPS, regardless of whether they are enabled or whether they are on a card. And it also includes whatever maps were pre-installed, such as the topo on an Oregon 600t for example.

Anyway, if you surpass this limit then some portions of maps will not show. Results vary depending on exactly what maps you are using. The only fix for this is to remove some of the maps.

[Durham Ranger]

Thank you to both jolly47roger and Boyd for your replies. I haven't had a chance to check out jolly47roger's suggestion yet. As to Boyd's suggestion I have to say I was concerned about how big (how many segments) the California Topo11 is. To address this I removed all maps from my GPSr and installed just one segment of the area I was having difficulty with. Interestingly, all the map data showed up on Base Camp but only the topo data showed up on the GPS,  none of the road data showed up.
Just to add to this, I also deleted all my maps from my GPS and then downloaded several of the segments from the California Topo (different map) and got the same results on both Base Camp and my GPS. All data showing on Base Camp, no roads on GPS.
I have not experienced any issues with either the Nevada or Arizona topos from GPS File Depot.
Additional thoughts?

[Boyd]

There's a bug on the Oregon 450 (and other models) that I don't think Garmin ever fixed. It could result in some map features not showing on the GPS. What profile do you have the Oregon set for? If it is not recreational, switch it to recreational.

If already set to recreational, set it to something else, exit from the menu, then return and re-select the recreational profile.

Don't know if this could be the problem, but it has helped others in the past so it's worth a try if you can't find anything else wrong.

[Durham Ranger]

Boyd, sorry for not responding to your reply sooner. When i initially tried your work around it didn't solve the problem. However, after putting it in recreational mode I deleted all maps off the GPS and reinstalled the catopo2011 which was giving me the problem. Problem solved (somewhat). All cal map segments are now showing with all data present. Even the ones that straddle the border into Az (this was where the problem was occurring).
Now I download the Az topo and where it overlaps into CA the cal topo is blank. It appears the overlapping map segments cancel each other out. So now I disable the AZ topo on the GPS and the cal topo is all good.
So now I try it in Geocaching mode and the cal topo overlap area is blank even with the Az topo disabled.
It would appear that the problem stems from overlapping map segments (Az and CA) and is further complicated by the mode feature.
Anyway, thanks to the helpful folks here (Boyd) and several hours installing and uninstalling maps and enabling and disabling them I now have a workaround.