diff --git a/setup/extensions.py b/setup/extensions.py
index faa1a3d88a..0d465f4a0a 100644
--- a/setup/extensions.py
+++ b/setup/extensions.py
@@ -375,9 +375,9 @@ class Build(Command):
             for x in (dest, dest+'.manifest'):
                 if os.path.exists(x):
                     os.remove(x)
-        shutil.rmtree(self.j(self.d(self.SRC), 'build'))
-
-
+        build_dir = self.j(self.d(self.SRC), 'build')
+        if os.path.exists(build_dir):
+            shutil.rmtree(build_dir)
 
 
 class BuildPDF2XML(Command):
diff --git a/setup/installer/__init__.py b/setup/installer/__init__.py
index 99e7586aa3..2acc5d4649 100644
--- a/setup/installer/__init__.py
+++ b/setup/installer/__init__.py
@@ -126,5 +126,5 @@ class VMInstaller(Command):
 
     def clean(self):
         installer = self.installer()
-        if os.patyh.exists(installer):
+        if os.path.exists(installer):
             os.remove(installer)
diff --git a/src/calibre/ebooks/pdb/ereader/reader132.py b/src/calibre/ebooks/pdb/ereader/reader132.py
index d2a1c006e3..cce1d40f8c 100644
--- a/src/calibre/ebooks/pdb/ereader/reader132.py
+++ b/src/calibre/ebooks/pdb/ereader/reader132.py
@@ -15,7 +15,6 @@ import zlib
 
 from calibre import CurrentDir
 from calibre.ebooks import DRMError
-from calibre.ebooks.compression.palmdoc import decompress_doc
 from calibre.ebooks.metadata.opf2 import OPFCreator
 from calibre.ebooks.pdb.ereader import EreaderError
 from calibre.ebooks.pdb.formatreader import FormatReader
@@ -79,6 +78,7 @@ class Reader132(FormatReader):
 
     def decompress_text(self, number):
         if self.header_record.compression == 2:
+            from calibre.ebooks.compression.palmdoc import decompress_doc
             return decompress_doc(self.section_data(number)).decode('cp1252' if self.encoding is None else self.encoding, 'replace')
         if self.header_record.compression == 10:
             return zlib.decompress(self.section_data(number)).decode('cp1252' if self.encoding is None else self.encoding, 'replace')
diff --git a/src/calibre/ebooks/pdb/ereader/reader202.py b/src/calibre/ebooks/pdb/ereader/reader202.py
index ce7ad1263a..a674c5bf60 100644
--- a/src/calibre/ebooks/pdb/ereader/reader202.py
+++ b/src/calibre/ebooks/pdb/ereader/reader202.py
@@ -12,7 +12,6 @@ import struct
 
 from calibre import CurrentDir
 from calibre.ebooks.metadata.opf2 import OPFCreator
-from calibre.ebooks.compression.palmdoc import decompress_doc
 from calibre.ebooks.pdb.formatreader import FormatReader
 from calibre.ebooks.pdb.ereader import EreaderError
 
@@ -55,7 +54,8 @@ class Reader202(FormatReader):
         return self.sections[number]
 
     def decompress_text(self, number):
-            return decompress_doc(''.join([chr(ord(x) ^ 0xA5) for x in self.section_data(number)])).decode('cp1252' if self.encoding is None else self.encoding, 'replace')
+        from calibre.ebooks.compression.palmdoc import decompress_doc
+        return decompress_doc(''.join([chr(ord(x) ^ 0xA5) for x in self.section_data(number)])).decode('cp1252' if self.encoding is None else self.encoding, 'replace')
 
     def get_image(self, number):
         name = None
diff --git a/src/calibre/ebooks/pdb/palmdoc/reader.py b/src/calibre/ebooks/pdb/palmdoc/reader.py
index 0a57e3f51a..ea7e6bbc2b 100644
--- a/src/calibre/ebooks/pdb/palmdoc/reader.py
+++ b/src/calibre/ebooks/pdb/palmdoc/reader.py
@@ -11,7 +11,6 @@ __docformat__ = 'restructuredtext en'
 import os
 import struct
 
-from calibre.ebooks.compression.palmdoc import decompress_doc
 from calibre.ebooks.pdb.formatreader import FormatReader
 from calibre.ebooks.txt.processor import convert_basic, opf_writer, \
     separate_paragraphs_single_line, separate_paragraphs_print_formatted
@@ -51,6 +50,7 @@ class Reader(FormatReader):
         if self.header_record.compression == 1:
             return self.section_data(number).decode('cp1252' if self.encoding is None else self.encoding)
         if self.header_record.compression == 2:
+            from calibre.ebooks.compression.palmdoc import decompress_doc
             return decompress_doc(self.section_data(number)).decode('cp1252' if self.encoding is None else self.encoding, 'replace')
         return ''
 
diff --git a/src/calibre/ebooks/pdb/palmdoc/writer.py b/src/calibre/ebooks/pdb/palmdoc/writer.py
index 91a5eb3d97..3f4a92fbed 100644
--- a/src/calibre/ebooks/pdb/palmdoc/writer.py
+++ b/src/calibre/ebooks/pdb/palmdoc/writer.py
@@ -10,7 +10,6 @@ __docformat__ = 'restructuredtext en'
 
 import struct
 
-from calibre.ebooks.compression.palmdoc import compress_doc
 from calibre.ebooks.pdb.formatwriter import FormatWriter
 from calibre.ebooks.pdb.header import PdbHeaderBuilder
 from calibre.ebooks.txt.txtml import TXTMLizer
@@ -25,6 +24,8 @@ class Writer(FormatWriter):
         self.log = log
 
     def write_content(self, oeb_book, out_stream, metadata=None):
+        from calibre.ebooks.compression.palmdoc import compress_doc
+
         title = self.opts.title if self.opts.title else oeb_book.metadata.title[0].value if oeb_book.metadata.title != [] else _('Unknown')
 
         txt_records, txt_length = self._generate_text(oeb_book)